503 html error

503 html error

Essentially, the 503 error is your first warning that something is preventing the browser from accessing the website server. This is where said server is unable. A 503 Service Unavailable Error is an HTTP response status code that indicates your web server operates properly, but it can't handle a. A 503 Service Unavailable Error is an HTTP response status code that indicates that your web server is functioning normally but is now unable to handle a.

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How To Fix ? WordPress Problem Error 503. Service Unavailable

503 html error - opinion

How to Fix the HTTP Error 503 Service Unavailable in WordPress

Running into errors on your WordPress site can be intimidating. However, most errors give you some clue as to what caused them, which can make troubleshooting these common issues a lot easier. The 503 error is not as polite, unfortunately, and doesn’t give you much information to go on.

It helps to understand what the most common causes are for the 503 error in WordPress. After that, you’ll need to be methodical when it comes to troubleshooting the error, which means following several steps in order to locate the root cause.

What's the HTTP 503 Service Unavailable Error?

The 503 error in WordPress signifies that your website can’t be reached at the present moment because the server in question is unavailable. This could happen because it’s too busy, under maintenance, or something else which requires a deeper analysis.

In this article, we’ll cover what the 503 error is and how it typically manifests. Then we’ll guide you through six steps in order to troubleshoot it. Let’s get to work!

What Is an HTTP Error 503?

The Internet Engineering Task Force (IETF) defines the 503 Service Unavailable as:

The 503 (Service Unavailable) status code indicates that the server is currently unable to handle the request due to a temporary overload or scheduled maintenance, which will likely be alleviated after some delay. The server MAY send a Retry-After header field to suggest an appropriate amount of time for the client to wait before retrying the request.

When you encounter the 503 error, it means that the server in question is unavailable. That could be because it’s too busy, for example, or it’s under maintenance. Unlike other similar error codes, 503 signifies that your website is online and running, but can’t be reached at the present moment.

What’s so vexing about this particular error is that it barely gives you any information to go on. Most of the time, it just shows up with a “Service temporarily unavailable” message. That’s the equivalent of calling a restaurant via phone, only to have them tell you that they’re closed but refuse to let you know when they’ll be open again.

If you’re lucky, the 503 error code will have occurred because your WordPress website is under maintenance. WordPress very briefly sets your site to maintenance mode when you’re updating a plugin, a theme, or the core software:

HTTP 503 Error in WordPress

Usually, this timeout is so brief that no one will notice it. However, in those cases where the 503 error persists, you’ll have a bigger problem to deal with. After all, not only will users be unable to visit your site, but you’ll lose access to your WordPress admin area as well. That means you can’t update your site in any way, and in order to troubleshoot it, you’ll need to dig into its files.

Check Out Our Video Guide to The 503 Error

503 Error Variations

The 503 error can show up in a lot of ways. However, almost every variation comes accompanied by that 503 code, making it easy to identify.

Here are some of the variations you might encounter, depending on your server configuration and browser:

  • 503 Service Unavailable
  • 503 Service Temporarily Unavailable
  • HTTP Server Error 503
  • HTTP Error 503
  • Error 503 Service Unavailable
  • The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Whatever the code you run into might look like, it means you need to get to work fast before it affects your users negatively.

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How to Fix the 503 Error in WordPress (6 Steps)

Since you often can’t be sure what caused the 503 error in any given situation, you’ll need to go about troubleshooting it methodically. The following six sections each cover a potential fix, aimed at resolving the different potential root causes.

After each step, take a moment to return to your website and see if the 503 error is gone. If it is, you’ve successfully fixed the issue. If not, continue on to the next step in the process.

1. Temporarily Deactivate Your WordPress Plugins

One of the most common causes of the 503 error in WordPress is plugin compatibility issues. To determine if that’s what’s happening, you’ll need to disable all of your site’s plugins.

Since the 503 error prevents you from accessing the WordPress admin area, you’ll need to use an FTP client for this step. If you don’t have one set up, we recommend FileZilla.

Once your FTP client is ready, connect to your website through it and navigate to your WordPress root folder. In case you can’t find it, it’s usually called public_html, html, public, www, or your site’s name. If you’re a Kinsta client, it’s your public folder.

WordPress root folder SFTP

Open that folder, and navigate to the wp-content directory. Inside, you’ll see a folder called plugins, which contains individual subdirectories for each of the plugins installed on your site (both active and inactive).

What you’re going to do now is right-click on the plugins folder, and rename it to something else. We recommend plugins.old or plugins.deactivated, so you can easily recognize it later.

WordPress plugins folder renamed

WordPress will now not be able to find any of your plugins. When that happens, it will automatically disable those plugins.

Now, try accessing your WordPress dashboard. If the 503 error is gone, then you can assume that one of your plugins was the culprit. All you have to do is figure out which one was at fault.

Return to the wp-content directory, and rename your original plugins folder correctly. Then, you’ll need to disable each of your plugins one by one, until you find the culprit.

To do this, open the wp-content/plugins directory. Inside, you’ll find one folder for each of your plugins. The process you’re going to follow is much the same as before:

  1. Start with the first folder, and rename it to anything you like.
  2. Check your website to see if the error is gone.
  3. If it isn’t, return the plugin folder from the previous step to its original name.
  4. Move on to the next plugin on your list, repeating the above steps.

This process can take a while if you have a lot of plugins, but it’s vital to check each plugin in turn. If at any point you identify the plugin that’s causing the error, you can uninstall it or replace it with another tool.

If you make it to the end of these steps without finding a solution, you can move on to the next stage of troubleshooting.

2. Deactivate Your WordPress Theme

Now that you’ve ruled out your plugins as the cause of the 503 error, it’s time to do the same with your active theme. In fact, your theme could also be creating compatibility issues.

Unfortunately, the process doesn’t work the same as above. WordPress won’t revert to the default theme if simply rename the theme folder, you would end up with an error like “The theme directory “theme name” does not exist.” Or if you try to rename the entire theme directory folder, you end up with “ERROR: The themes directory is either empty or doesn’t exist. Please check your installation.”

The theme directory does not exist error

Therefore, you need to access your WordPress database by logging into phpMyAdmin. If you’re a Kinsta client, this can be found within the “Info” section of the MyKinsta dashboard.

MyKinsta phpMyAdmin

Click into the “wp_options” table, then click on the “Search” tab. You will want to search under the “option_name” for template.

phpMyAdmin wp_options table

Under the “option_value” column you will see the current name of your theme. Change this to one of the default themes, such as “twentynineteen.”

wp_options template name

Check your website again to see if this has fixed the error. If it did, it simply means it’s a problem with your WordPress theme and you might want to try reinstalling it or reverting to your most recent backup.

3. Temporarily Disable Your Content Delivery Network (CDN)

Sometimes, the 503 error will show up not because of a problem on your website, but because of your Content Delivery Network (CDN). If you’re using a CDN, a quick way to figure out if that’s the case is to temporarily disable it.

Every CDN should include some feature that enables you to pause its services. If you’re on Kinsta, you can disable your Kinsta CDN by navigating to CDN → “Disable CDN” inside your MyKinsta dashboard:

MyKinsta CDN enable/disable option

The process you need to follow may be different depending on which CDN you’re using. Cloudflare has also been known to cause 503 errors sometimes. If you can’t find the option to pause yours, check out your service’s knowledge base, which will usually contain detailed instructions.

If you don’t use a CDN or find that pausing your service doesn’t help with your issue, there are still a few more fixes to try. Do remember to reactivate your CDN before moving on.

4. Limit the WordPress ‘Heartbeat’ API

The WordPress Heartbeat is an API built into WordPress, which the platform uses for auto-saving content, showing you plugin notifications, letting you know when someone else is working on a post you’re trying to access, and more.

Just like a regular heartbeat, the API works in the background with a high frequency so that it doesn’t miss anything. As you might imagine, this API consumes server resources. Usually, that’s not a problem but in some cases, it may lead to a 503 error if your server can’t handle the load.

The quickest way to determine if the Heartbeat API is at the center of your problems is to temporarily disable it. To do that, connect to your WordPress website via FTP once more, and then open your current themes folder and look for the functions.php file within:

WordPress theme functions.php file

Right-click on the file and select the View/Edit option, which will open it using your local text editor. Once it’s open, you’ll need to add the following code snippet within:

Those three lines of code tell WordPress to disable the Heartbeat API. Save the changes to the functions.php file, close it, and try to access your website again.

If the 503 error is gone, you’ll know that the API was the problem. Disabling it altogether removes a lot of useful functionality, however. Instead, we recommend that you ‘slow down’ the Heartbeat, so that it doesn’t cause problems.

The easiest way to do that is by installing the Heartbeat Control plugin. Activate the plugin and navigate to the Settings > Heartbeat Control section. Look for the Modify Heartbeat options, and drop the frequency to the lowest possible number:

Heartbeat Control plugin frequency

Save the changes to your settings and return to the functions.php file you tweaked a while back. For the above changes to work, you’ll need to remove the string of code you added before and save your changes to the file.

At this stage, the 503 error should be gone if the Heartbeat API was the problem. If it isn’t, then it’s time to try something different.

5. Increase Your Server’s Resources

If the 503 error is still occurring despite all your attempts to fix it so far, then there’s a good chance the problem might be due to a lack of server resources. That is to say, you’ll need to upgrade your hosting plan to see if that fixes the issue. This is especially true if you’re using cheap WordPress hosting, as they tend to throttle resources. We don’t do this at Kinsta.

Upgrading your plan is a big decision, however. The smart move is to first contact your web hosting support service and discuss the 503 error with them, as well as the steps you’ve taken so far to try and solve it. The support team should be able to help you work out the cause and advise you on whether you need to upgrade your plan or not.

6. Review Your Logs and Enable WP_DEBUG

You should also take advantage of your error logs. If you’re a Kinsta client, you can easily see errors in the log viewer and enable WordPress debug mode in the MyKinsta dashboard. This can help you quickly narrow down the issue, especially if it’s resulting from a plugin on your site.

Check error logs for HTTP 503 errors

If your host doesn’t have a logging tool, you can also add the following code to your wp-config.php file to enable logging:

The logs are typically located in the /wp-content directory. Inside it, look for a file called debug.log and open it up.

Others, like here at Kinsta might have a dedicated folder called “logs”.

WordPress error logs folder (SFTP)

Interpreting your debug log can be a bit intimidating but it’s not as hard to read as you might imagine. In a nutshell, the log contains each error that pops up on your site in chronological order. It shows which file caused each error, as well as which specific lines of code were involved.

Beware: you’re not going to find direct references to the 503 error within your log. Even so, if all else fails, it can point you in the right direction by showing you what files are causing problems. That way, you’ll know where to focus your efforts next. As we mentioned in the previous step, now is a good time to get in touch with your hosting provider if you need further assistance resolving this error.

You can also check the log files in Apache and Nginx, which are commonly located here:

  • Apache: /var/log/apache2/error.log
  • Nginx: /var/log/nginx/error.log

To learn more, please check out our web server showdown: Nginx vs Apache.

If you’re a Kinsta client you can also take advantage of our analytics tool to get a breakdown of the total number of 503 errors and see how often and when they are occurring. This can help you troubleshoot if this is an ongoing issue, or perhaps something that has resolved itself.

If the 503 error is displaying because of a fatal PHP error, you can also try enabling PHP error reporting. Simply add the following code to the file throwing the error. Typically you can narrow down the file in the console tab of Google Chrome DevTools.

And you might need to also modify your php.ini file with the following:


If you’re lucky, the 503 error will only show up when you put your website into maintenance mode. However, if it appears without warning, then you’ll have to roll up your sleeves and do some troubleshooting.

To get at the root cause of the 503 error, you’ll need to follow these steps to fix it:

  • Temporarily deactivate your WordPress plugins.
  • Deactivate your WordPress theme.
  • Disable your CDN.
  • Limit the WordPress Heartbeat API.
  • Increase your server resources.
  • Review your logs and enable WP_DEBUG.

Have you ever run into the HTTP 503 error in WordPress? Share your experiences with us in the comments section below!

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What is HTTP error 503 and how do you fix it?

An HTTP 503 error is encountered when your browser encounters a website that is unable to establish a connection with its server.

Many people seem to confuse this for the classic 502 bad gateway, but it's a slightly more troubling issue, particularly if you're not an experienced IT professional.

If you're lucky, simply refreshing the page can and should resolve the issue, but there will be times when this easy fix is not enough.

While it might be worth troubleshooting for issues on your own network, in the majority of cases, a 503 error is caused by issues with the web server that the browser is trying to reach. If that is the case, there isn't much one can do aside from reaching out to the IT admin that runs the page, if you even have that information to hand.

What does HTTP error 503 mean?

Essentially, the 503 error is your first warning that something is preventing the browser from accessing the website server. This is where said server is unable to deal with the information requested, though the exact cause won't be made clear at the time. Often you'll just get the annoyingly vague advice to 'try again later'.

​A number of popular sites had 503 issues last year due to the infamous Fastly outage. That included payment sites such as PayPal and Shopify, internet forums like Quora and Reddit, and also streaming giants like Spotify and Twitch. This also affected gov.uk, as well as numerous online newspapers and news outlets, including the New York Times, BBC, Financial Times, CNN, the Guardian, Bloomberg News, and The Verge, with the latter having to use Google Docs to publish stories.

While many of the websites showed the "503 error", the cloud computing services provider described the issue as a "global CDN disruption", with its own website displaying an "I/O error" message.

What causes an HTTP error 503?

Example of an HTTP 503 error

When met with an HTTP error 503, the first question is usually “why?”, coupled with the hope that determining the cause of the issue will help us solve it quickly and painlessly. Unfortunately, this is not always the case.

Similar to other HTTP errors, determining the root cause of the Error 503 is much harder than one would expect – especially without technical IT expertise. However, there are a few possible scenarios that can be considered as plausible causes for an HTTP error 503.

In the majority of cases, the 503 is triggered when the website in question is no longer able to connect with its supported server, meaning that any information requested or issued by your browser is simply hitting a wall. This usually happens when the server experiences a technical issue, is undergoing maintenance works, or is facing some sort of malicious disruption, such as a denial of service (DDoS) attack. Regardless of the cause, this information will likely not be readily available.

Frequent technical issues, such as those occurring multiple times a month, can be especially disruptive and excessive downtime can cause serious financial difficulty – especially if it heavily depends on online traffic or orders made through e-commerce. Perhaps the best example of this is Amazon's Prime Day disruption in 2018, which should serve as a blueprint for businesses in how not to handle an outage.

Hence, if your website is displaying an HTTP error 503 more often than its own home page, it might be worth switching hosting providers.

Although an HTTP error 503 can diminish the number of customers visiting the site, it can also be caused by an inundation of visitors, such as during seasonal sales. In these cases, the server remains connected, yet is incapable of supporting the avalanche of requests from many different users.

Alternatively, this can also be caused by malicious traffic instead of eager customers, such as in the case of distributed denial of service (DDoS) attacks. Misconfigured web apps may also cause a 503 error to appear, such as a plugin conflict caused by WordPress, while regular 503 errors could suggest an issue with the domain name system (DNS), whether that's an incorrect server configuration or an issue with the DNS server itself.

How to fix an HTTP error 503

The fastest method to resurrect the site you're trying to access is by refreshing the web page and hoping that this will solve the problem.

However, there are also several other steps you can take to make sure the problem isn't linked to your connection. For example, you can restart your router or computer. If an error message shows "Service Unavailable – DNS Failure", then this usually means there may be an error with your hardware configuration, which thankfully can be corrected by performing a reboot. You might find there is a problem with the allocated DNS server, but this is normally resolved by choosing to use a different DNS server.

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However, if the 503 error is a result of a problem found on the server's side, then unfortunately there isn't a lot you can do yourself to remedy it. This is where the IT administrator for the site should troubleshoot the issue to find a solution to the fault that users are reporting if they are encountering HTTP 503 errors. If you find yourself in that position and discover that updates need to be applied to a site, it's recommended to schedule them when your site's traffic is likely to be lowest, so your users don't regularly come across errors.

Alternatively, if recurring HTTP 503 errors are regularly caused by traffic spikes, it's best to use this as a sign that you might want to increase your web server resources investment. In addition to this, a surge of traffic could be the result of a denial of service (DoS) attack, in which case it might be a clever idea to approach your hosting provider to ask about the possible mitigations they can offer you to prevent attacks in the future.

Further investing in security protections or increasing the frequency of patch management could also serve to prevent any subsequent incidents from occurring. Several providers already include DDoS protection as part of their default packages, which may restrict the number of users that are allowed to access a site at any one time.

Finally, should the HTTP 503 error be a result of a programming bug, you'll need to undergo further investigation to pinpoint the issue and rectify it permanently.

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A 503 Service Unavailable Error happens when a web server is temporarily unable to handle a request that’s been made of it. Almost always, the error is on the website itself and there’s nothing you can do about it but try again later. Still, there are a few quick things you can try on your end.

What is a 503 Service Unavailable Error?

A 503 Service Unavailable Error indicates that a web server is temporarily unable to handle a request. That could be the web server you’re trying to access directly, or another server that web server is in turn trying to access. It’s called a 503 error because that’s the HTTP status code that the web server uses to define that kind of error. The error can occur for a number of reasons, but the two most common reasons are that the server is overwhelmed with requests or is having maintenance performed on it.

The 503 error is different from a 500 Internal Server Error. The 500 error occurs when something is preventing the server from handling your request, while the 503 Error actually means that the server is fine—it’s able to process your request and is returning the 503 error by design.

Just like with other errors like this, website designers can customize how a 503 error looks. So, you might see different looking 503 pages on different websites. Websites might also use slightly different names for this error. For example, you might see things like:

  • Http/1.1 Service Unavailable
  • 503 Error
  • 503 Service Temporarily Available
  • 503 Service Unavailable
  • Service Unavailable – DNS Failure
  • HTTP Error 503
  • HTTP 503
  • Error 503 Service Unavailable

An important thing to remember is that the 503 error is a server-side error. That means the problem exists with the website you’re trying to access, and not with your computer. That’s both good and bad news. It’s good news because there’s nothing wrong with your computer, and it’s bad news because there’s usually nothing you can do to solve the problem from your end.

Nonetheless, here are few quick things you can try.

Refresh the page

As we mentioned, a 503 error indicates a temporary problem, and sometimes that problem is very temporary. A site might be getting overwhelmed with traffic, for example. So, refreshing the page is always worth a shot. Most browsers use the F5 key to refresh, and also provide a Refresh button somewhere on the address bar. It doesn’t fix the problem very often, but it takes just a second to try.

Warning: Be sure to pay extra attention if the error occurs while you’re making a payment. Refreshing the page might get you charged twice, so keep an eye out for that.

Check If the Site Is Down For Other People

Whenever you fail to reach a site (for whatever reason), you can also check if it’s just you that’s having a problem connecting, or if other people are having the same trouble. There are lots of tools out there for this, but our favorites are isitdownrightnow.com and downforeveryoneorjustme.com. Both work pretty much the same. Plug in the URL you want to check, and you’ll get a result like this.

If you get a report saying the site is down for everyone, there’s not much you can do but try again later. If the report shows that the site is up, then the problem might be on your end. It’s very rare this is the case with a 503 error, but it is possible, and you can try some of the things we describe in the next couple of sections.

Restart Your Devices

So, you’ve used a site checking tool and determined that the site is just down for you. And, you’ve tested another browser and are having the same problem. This tells you the problem is likely something on your end, but it’s not your browser.

It is possible that there are some strange, temporary issues with your computer or your networking equipment (Wi-Fi, router, modem, etc.). A simple restart of your computer and your networking devices might help fix the problem.

Another possibility is that the error is caused by a DNS issue but on a DNS server rather than your computer. In that case, you can try switching DNS servers and seeing whether the problem gets resolved.

Contact the Website

Another option is to contact the website owner directly. Look up their contact information on the website and contact them about the page in question. If there is no contact form, you can try and reach the website on their social media.

Image Credit: Micha/Shutterstock HTTP Error 503

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The server returns an HTTP error 503 when more users than are allowed by the server's request queue limit have sent requests to a single server or when the actions of the client have triggered throttling.

The error returned by the server resembles the following.

 OPTIONS /Microsoft-Server-ActiveSync  Content-Type: application/vnd.ms-sync.wbxml  MS-ASProtocolVersion: 14.0    HTTP/1.1 503 Service Unavailable  Connection: close  Date: Mon, 02 Mar 2009 23:51:51 GMT  Server: Microsoft-IIS/7.0  X-Powered-By: ASP.NET  Content-Type: text/html

If a Retry-After header ([RFC2616]) is present in the response, the client SHOULD<6> retry the request after waiting the number of seconds indicated by the Retry-After header. Any such value represents an estimate of when the server is expected to be able to process the request.

If a Retry-Header is not present in the response, the client can retry the request after waiting a few seconds. The time to wait between continuous requests that result in HTTP error 503 responses can be increased exponentially to a predetermined maximum.

For more details about ASP.NET performance monitoring properties, see [MSDN-APM].

Imagine someone searches for a topic and finds your website on page one of Google. When they click through to your website, though, their eyes land on a bland webpage that says "Service Unavailable".

What do you think they'll do when they find your website on Google again? Odds are, they'll skip over it and click on the next link. If visitors are looking for answers and you're promising them those answers, but you can't deliver because something's wrong with your website, they'll lose trust in your brand.

Unfortunately, if your website experiences a 503 Service Unavailable Error, there's no silver bullet solution. You have to investigate what's actually causing the issue, because even though these types of errors indicate what happened to your website, they don't tell you why it happened.

To help you fix your 503 Service Unavailable Error and avoid losing potential customers, check out our guide on what exactly the issue is and its most common solutions.

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What is a 503 error?

A 503 Service Unavailable Error is an HTTP response status code that indicates your web server operates properly, but it can't handle a request at the moment. Since it's just a generic error message, it's difficult to pinpoint the issue's exact cause.

When your website is experiencing a 503 Service Unavailable Error, your site's visitors will land on an error page. Fortunately, Airbrake recommends five common solutions for troubleshooting most 503 Service Unavailable Errors.

How to Fix an HTTP Error 503

  1. Reboot your server.
  2. Check to see if your web server is going through maintenance.
  3. Fix faulty firewall configurations.
  4. Sift through your server-side logs.
  5. Comb through your website's code to find bugs.

1. Restart your server.

Sometimes, there will be congestion in the server chain that hosts your website. One of the most effective ways to open up and refresh it is to simply restart your web server. If your website is hosted on multiple servers, make sure you restart all of them to get it running again.

2. Check to see if your web server is going through maintenance.

Most web servers shut down when they're going through maintenance. If you can access your server's administration settings, check the configuration options to see when automatic maintenance sessions are scheduled. If you'd rather have complete control over your server's maintenance, you can disable these automatic updates in the configuration options, too.

3. Fix faulty firewall configurations.

Your firewall is your website's gatekeeper, protecting your site from malicious visitors or distributed denial-of-service (DDoS) attacks. Sometimes, a faulty firewall configuration will cause your firewall to deem requests from a content delivery network as an attack on your server and reject them, resulting in a 503 Service Unavailable Error. Check your firewall configuration to pinpoint and fix the issue.

4. Sift through your server-side logs.

There are two types of server-side logs -- applications logs and server logs. Application logs recount your website's entire history, letting you see the web pages requested by visitors and the servers it connected to. Server logs provide information about the hardware running your server, revealing details about its health and status. Sift through both types of server-side logs to uncover any alarming information about your server or website.

5. Comb through your website's code to find bugs.

If there's a mistake in your website's code, your web server might not be able to correctly answer requests from a content delivery network. Comb through your code to find bugs or copy your code into a development machine. It'll perform a thorough debug process that will simulate the exact situation your 503 Service Unavailable Error occurred in and allow you to find the exact moment things went wrong.

Any time there's an error on your site, it's important to fix it as soon as you can. If customers get errors, they probably won't come back to your page.

Editor's note: This post was originally published in January 2019 and has been updated for comprehensiveness.


503 Service Unavailable Error Message: What It Is and How to Fix It

The 503 Service Unavailable error is an HTTP status code that means a website's server is not available right now. Most of the time, it occurs because the server is too busy or maintenance is being performed on it.

A 503 error message can be customized by the website it appears on or the server software that generates it, so how you might see it vary greatly.

How to Fix the 503 Service Unavailable Error

Since the 503 Service Unavailable error is a server-side error, the problem is usually with the website's server. Your computer may have an issue causing the 503 error, but it's not likely.

Regardless, there are a few things you can try:

  1. Retry the URL from the address bar again by selecting Reload or Refresh, the F5 key,or the Ctrl+R keyboard shortcut.

    Even though the 503 Service Unavailable error means there's an error on another computer, the issue is probably only temporary. Sometimes just trying the page again will work.

    If the 503 Service Unavailable error message appears while paying for an online purchase, be aware that multiple attempts to check out may end up creating multiple orders and multiple charges. Most payment systems and some credit card companies have protections from this kind of thing, but it's still something you should know.

  2. Restart your router and modem. Then restart your computer or device, especially if you see the Service Unavailable - DNS Failure error.

    While the 503 error is still most likely the fault of the website you're visiting, there may be an issue with the DNS server configurations on your router or computer, which a simple restart of both might correct.

  3. Another option is to contact the website directly for help. There's a good chance that the site's administrators already know about the 503 error, but letting them know, or checking the status on the problem, isn't a bad idea.

    Most sites have support-based social network accounts, and some even have phone numbers and email addresses.

    If the website giving the 503 error is a popular one, and you think it might be down completely, check if the website is down by plugging its URL into a service like Freshping's Is it down tool. A smart Twitter search can usually give you the answer, too. Try searching for #websitedown on Twitter, replacing website with the site name, as in #facebookdown or #youtubedown. An outage on a prominent site will usually generate lots of talk on Twitter.

  4. Come back later. Since the 503 Service Unavailable error is a common error message on trendy websites when a massive increase in traffic by visitors is overwhelming the servers, simply waiting it out is often your best bet. Frankly, this is the most likely "fix" for a 503 error. As more and more visitors leave the website, the chances of a successful page load for you increase.

Fixing 503 Errors on Your Own Site

With so many different web server options out there and even more general reasons why your service might be unavailable, there isn't a straightforward "thing to go do" if your site is giving your users a 503.

That said, there are certainly some places to start looking for a problem and then hopefully a solution.

Start by taking the message literally—has something crashed? Restart running processes and see if that helps.

Beyond that, look at not-so-obvious places where something might have hiccuped. Where applicable, look at connection limits, bandwidth throttling, overall system resources, fail-safes that might have triggered, etc.

In what's very likely a "double-edged sword" for your website, it may be that it's suddenly very, very popular. Getting more traffic than you built your site to handle almost always triggers a 503.

However, the 503 error could also result from a malicious denial of service (DoS) attack. If so, getting into contact with the company hosting your website would be wise to discuss steps that you can take to reduce the likelihood of it happening again or to better prepare for another in the future.

Even an unintentional DoS attack can occur, where a virus on the server is sucking away usable system resources and slowing the server down to the point that it causes a 503 error.

Most Common Ways You Might See the 503 Error

503 Service Unavailable errors can appear in any browser in any operating system, including Windows 10 back through Windows XP, macOS, Linux, etc...even your smartphone or other nontraditional computers. If it has internet access, you could see a 503 in certain situations.

Here are the most common ways you might see the "service unavailable" error:

  • 503 Service Unavailable
  • 503 Service Temporarily Unavailable
  • Http/1.1 Service Unavailable
  • HTTP Server Error 503
  • Service Unavailable - DNS Failure
  • 503 Error
  • HTTP 503
  • HTTP Error 503
  • Error 503 Service Unavailable
  • Error 503 Backend fetch failed

The 503 Service Unavailable error displays inside the browser window, just as web pages do.

Sites that use Microsoft IIS may provide more specific information about the cause of a 503 Service Unavailable error by suffixing a number after the 503, as in HTTP Error 503.2 - Service Unavailable, which means Concurrent request limit exceeded. See More Ways You Might See a 503 Error near the bottom of the page for the whole list.

More Ways You Might See a 503 Error

In Windows applications that inherently access the internet, a 503 error might return with the HTTP_STATUS_SERVICE_UNAVAIL error, and maybe also with a The service is temporarily overloaded message.

Windows Update might also report an HTTP 503 error, but it will display as error code 0x80244022 or with a WU_E_PT_HTTP_STATUS_SERVICE_UNAVAIL message.

Some less common messages include 503 Over Quota and Connection Failed (503), but the troubleshooting above applies all the same.

If the website that reports the 503 error happens to be running Microsoft's IIS web server software, you might get a more specific error message like one of these:

IIS 503 Errors
Status CodeReason Phrase
503.0Application pool unavailable
503.2Concurrent request limit exceeded
503.3ASP.NET queue full
503.4FastCGI queue full

Errors Like 503 Service Unavailable

The 503 Service Unavailable error is a server-side error. It's very much related to other server-side errors like the 500 Internal Server Error, the 502 Bad Gateway error, and the 504 Gateway Timeout error, among others.

Several client-side HTTP status codes exist, too, like the standard 404 Not Found error, among others. 


  • You can encounter a 503 error pretty much any time you're visiting a website or using an online service. It's sometimes possible to anticipate these errors, such as when a small website suddenly receives an unexpected surge in attention it wasn't built for. However, more often than not it comes down to timing and bad luck whether or not you'll encounter one.

  • Yes. It can also appear as Varnish Cache Server: Error 503 Service Unavailable or Error 503: Backend Unhealthy or error when calling aws apis. error details - serializationerror: 503 service unavailable. Regardless of how the message appears, the main terms to look out for are 503 and Error.

  • This probably means that whatever website you've set as Safari's home page default is experiencing trouble. Aside from waiting a bit and trying again, or restarting Safari or your Mac, you can also change Safari's home page to a different URL.

Thanks for letting us know!

A 503 Service Unavailable Error is an HTTP response status code indicating that your web server operates properly, but it can't temporarily handle the request at the moment. This error happen for a wide variety of reasons. Normally, this error can be due to a temporary overloading or maintenance being performed on the server and it is resolved after a period of time or once another thread has been released by web-server application.

what is 503 Service Unavailable Error

In most cases this could happen (assuming there are no faults in your app) if there are long running tasks and as a result the request queue is backed up. Almost always, the 503 Service Unavailable Error is on the website itself and there's nothing you can do about it but try again later.

503 Error Messages

Here are the most common ways you might see the service unavailable error:

  1. HTTP Error 503 The service is unavailable
  2. HTTP 503
  3. HTTP Error 503
  4. 503 Error
  5. Status code HTTP Error 503
  6. HTTP Server Error 503
  7. Error 503 Service Unavailable
  8. 503 Service Unavailable Error
  9. 503 Service Temporarily Unavailable
  10. Service Unavailable – DNS Failure
  11. HTTP /1.1 Service Unavailable

How to fix HTTP 503 errors

Troubleshooting on the Client-Side

Reload (Refresh) the page

Click the reload button on your web browser or press F5 on your keyboard to reload the webpage. Then check to see if your HTTP Error 503 disappears.

Restart Your Devices

reboot Your Devices

There should be a chance that the web-server not able to find the appropriate source file from its location and there should be some incorrect configurations happened on the DNS server configurations from client side (router or computer), which a simple restart of both might correct.

Scan for Malware

If you are sure to the website is up and running for other people, there's a good chance that this error is caused by malware infection . These malware codes can cause many problems in your system, including blocking access to your favourite websites. Scan your computer thoroughly with antivirus software .

Clear Temporary Files

Clear Temporary Files disk cleanup

Over time, your system accumulates junk files from normal web browsing and computer use. If this junk isn't occasionally cleaned out, it will cause Windows Operating System to respond slowly or provides a Service Unavailable error, possibly due to file conflicts or an overloaded hard drive. Disk Cleanup is a useful built-in Windows tool that can quickly remove temporary files from your system.

Visiting the website later

If you have Refresh your web-page and restarted your devices, and still problem persists, it is likely that your 503 Service Unavailable error comes from the web server. As mentioned above, temporary overloading or maintenance being performed on the server. What you can do is to wait a little while, and then try accessing the site (or running the application) again. You will be able to visit the problem website when a number of visitors has left the site or the server has been repaired by the administrator.

Contact server admin

If you still get an error, it may be useful to contact the appropriate administrator or support, if it's available. Most sites have support based social media accounts and some even have phone numbers and email addresses.

Troubleshooting on the Server-Side

Troubleshooting on we servers

Reboot the Web Server

Actually, error 503 Service Unavailable code can be a result of bottleneck in the server chain that hosts your application. If you or an web admin have the ability to do so, one of the simplest solution is by restarting the server hosting the application. Make sure all servers are rebooted in the proper manner. You can bring the website back to normal by rebooting the server.

Server Connectivity Issues

webserver Server Connectivity

Modern applications don't reside on a single server , instead, be spread over multiple servers. This error can also be a signal that there is something wrong in the server chain. Maybe one part of the server chain is down or unreachable, which leads to HTTP error 503 service unavailable. Thus, finding out the real faulty section is your 503 service unavailable fix.

Improper Firewall Configuration

Your Firewall is the gatekeeper of your web-server and it blocks potentially harmful data stream. However, it's entirely possible for a firewall configured somewhere on the network in which your application is running to be preventing some form of critical traffic from getting through. So, Check your firewall configuration to pinpoint and fix the issue.

Check the Logs

webserver application logs

Application logs are typically the history of what the application did, such as which pages were requested , which servers it connected to, which database results it provides, and so forth. Therefore, you can check the logs with not only the health and status of all connected services, but also the server itself.

Lastly, if the error is due to a programming error , further investigation will be required to pinpoint the issue and take steps to correct it.

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