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Maybe you were excited to check on your WordPress website’s latest metrics. Perhaps a confused customer told you that your website isn’t working. Or maybe you were about to show off your spiffy new landing page. Now, you’re staring down a 503 service unavailable error.

It’s anxiety-inducing to realize your website is inaccessible to visitors and your business momentum is sidetracked — especially when you don’t know what caused the issue or how to fix it based on a vague error code.

Like most WordPress website owners who have encountered this error, you need guidance to address the outage and restore normal website operation. This comprehensive guide will cover what causes WordPress 503 errors, how to fix them and how to prevent them.

Understanding 503 errors in WordPress

A 503 error indicates your web server couldn’t respond to a request from your WordPress website. Typically, 503 errors stem from surges in traffic or activity that temporarily exhausts your allocated server resources beyond capacity. It doesn’t mean the host server has completely shut down or been disabled.

For example, imagine you recently finished launching a marketing plan. Your web analytics indicate increased page views — but then, your website starts displaying the 503 error. Possibly, a traffic spike flooded the server with more concurrent visitors than it’s configured to handle.

In most scenarios, once resources fall within operable limits again, websites automatically restore normal functioning and stop displaying 503 warnings. However, suffering service disruptions on multiple occasions will cause reputational harm and impact your revenue.

Notably, some 503 errors directly stem from dysfunctional code that prevents server communication. Unless you fix the core script issues, these issues could endlessly recur — known as 503 jail. This guide will explain how to attend to these conflicts and glitches.

You’re already on the right track to avoiding negative user experiences and frustration. The next step is learning more about the 503 error’s triggers, which is crucial because the fix depends on the cause. Your diagnosis will change whether you upgrade your hosting plan, patiently wait for usage to subside or actively debug your website.

What causes 503 errors?

You’re about to learn seven potential causes of WordPress 503 errors.

The seven causes of 503 errors in WordPress.

Faulty plugins

Plugins are installed on WordPress websites to add features and functionalities; sometimes, plugins are an unwitting culprit behind 503 errors. Broken plugins can lead to inefficient resource usage and communication hiccups between websites and servers.

When plugins inadvertently trigger little problems that accumulate or a struggling process abruptly fails, it can exhaust server resources, which leads to the 503 warning message. Websites that rely on flawed or resource-intensive plugins are susceptible to this problem — it’s annoying yet one of the more common WordPress issues.

Removing or fixing troublesome plugins and finding lighter, better-coded alternatives is a path to more reliable performance.

Theme issues

Themes power WordPress websites yet can trigger pesky errors in unfortunate cases. Without theme efficiency and optimization, websites may falter and fail temporarily, resulting in WordPress 503 error warnings.

Specifically, some themes contain coding bugs within key files like functions.php. This can disrupt communication between servers and websites, essentially blocking resource access requests and processes from completing successfully.

Identifying and replacing buggy themes with well-coded alternatives can swiftly resolve the associated server load issues. This approach provides another rapid fix for your website.

Exceeding resource limits

Websites operate within limited computing resources on hosting plans. When traffic and activity spike beyond your allocated amounts, it’s trouble.

Too many visitors accessing a website at once can overwhelm available capacity. Other usage jumps are linked to mass exporting data from a database. Excessive emails, large uploads and resource mismanagement will contribute too.

Just like overfilling a cup, extending websites beyond their container servers can get messy, as evidenced by 503 warnings. To counteract this, use server activity monitoring tools to track usage surges before they become disruptive.

If your website is overtaxing the server or cutting it close, upgrade your hosting plan with more resources to avoid service disruptions. Try Bluehost’s Pro plan, which is optimized for high traffic and comes with a free content delivery network (CDN).

Maintenance mode

Website owners sometimes trigger 503 errors by putting websites into maintenance mode, typically to perform development backstage.

While maintenance mode is convenient and useful, it temporarily blocks traffic in order to finish updates seamlessly without disruptions. Accidentally leaving maintenance mode enabled will leave visitors with a frustrating 503 blocked access page.

Worse yet, due to the sudden drop in engagement metrics, search engines may penalize websites for long-term maintenance.

Check your admin settings to ensure the maintenance mode toggle is correctly switched off. Now that you know this web dev quirk, you can build websites worry-free and your updates won’t bring problems — they’ll bring improvements.

DDoS Attacks

Cyberattacks like DDoS (distributed denial-of-service) bombard servers, intentionally triggering service disruptions. Malicious actors overload systems with redundant requests from multiple sources. Predictably, this exhausts the resources allocated to hosting your WordPress website.

A barrage of access attempts can lead servers to fail with website-wide 503 errors. Bluehost clients enjoy a team of tech experts who work quickly to thwart and avoid frustrating downtime and business disruption.

How to prevent DDoS attacks.

Your web host will have a cyberattack response plan, but there are steps you can take yourself. Safeguards like firewalls mitigate cyberattacks that occur unexpectedly through no fault of website owners.

Bad code snippets

Some people customize their websites by inserting WordPress code snippets meant to add helpful functions. Much like how some plugins and themes contain misguided instructions or cause conflicts, handwritten custom code can contain risks.

When inserting code snippets, typing just one wrong character can trigger more harm than good. When faulty code snippets result in failed processes that prevent your website from correctly accessing its hosting container, it can manifest as a 503 warning.

While code experiments enable innovative advancements, thoroughly debug new additions in staging environments. This insulates your public-facing website from mishaps.

While code experiments enable innovative advancements, thoroughly debug new additions in staging environments. This insulates your public-facing website from mishaps.

Server outages and glitches

Even reliable servers occasionally suffer unexpected glitches, leading to temporary issues. Usually, glitches are minor hiccups like configuration file errors that misdirect requests for a few websites while others remain unaffected.

Regardless of scale, these disruptive incidents can overload server capacities, eventually blocking traffic with 503 WordPress errors. Extensive monitoring enables tech support to kick off reboot sequences rapidly if your automated checks ever detect unhealthy vitals.

How long do 503 errors last?

The duration of 503 errors depends heavily on the underlying trigger. In the case of transient resource constraints due to server glitches or unexpected traffic spikes, websites automatically restore normal operations within hours once usage levels return to an acceptable range.

In a way, the 503 error acts as an automatic safety mechanism; it prevents extended outages by halting service temporarily instead of waiting until the website crashes altogether.

In a way, the 503 error acts as an automatic safety mechanism; it prevents extended outages by halting service temporarily instead of waiting until the website crashes altogether.

On the other hand, errors caused by plugin folder conflicts, theme bugs or problematic code snippets require deliberate troubleshooting to address root causes.

Basically, WordPress 503 errors tied to configuration problems are likely to persist. Pinpointing the error’s origins will guide your approach — let’s jump into diagnosing your situation so you can either allow natural recovery, debug website issues or tweak your hosting plan.

How to fix a 503 error on WordPress

  1. Contact your hosting provider
  2. Deactivate plugins
  3. Adjust resource usage
  4. Switch themes
  5. Enable debug mode
  6. Check server logs
  7. Restore from a backup

These steps will lead you through troubleshooting WordPress 503 errors based on the most common causes.

Navigate to your website in your browser. After each troubleshooting approach, hit refresh on your website to verify whether the HTTP error is solved.

How to troubleshoot the WordPress 503 error message based on diagnosis.

Contact your hosting provider

Dedicated technical support teams can troubleshoot even the most complex causes of persistent 503 errors — plus, you won’t need to watch tutorials about cPanel, FTP clients and the WordPress dashboard.

Now that you know a lot about 503 errors and why they happen, you can clearly describe the symptoms to Bluehost’s 24/7 support team and get your WordPress 503 error resolved.

Now that you know a lot about 503 errors and why they happen, you can clearly describe the symptoms to Bluehost’s 24/7 support team and get your WordPress 503 error resolved.

Our experts can dive into server activity error logs, scan for software conflicts, review account resource usage, check security levels and determine any recent changes potentially linked to the sudden issues.

We have more resources and expertise to find the root cause quickly, ensuring you can get back to business.

Head to Bluehost’s support page if your WordPress 503 errors persist.

If you’re a do-it-yourself type of person, try some of the fixes below.

Deactivate plugins

Outdated, inefficiently coded or overly resource-intensive plugins can play a role in inadvertently triggering website failures marked by 503 service unavailable messages.

Rather than guess which specific add-on might be the culprit, website owners should temporarily turn off all plugins at once and see whether their website comes back online.

Using an FTP client like Filezilla, navigate to your WordPress installation, specifically the public_html folder. Locate the wp-content directory to access plugins, themes and key files. Rename the /wp-content/plugins/ folder to anything else — this deactivates all plugins without losing settings.

Keep tabs on your website. If disabling all plugins resolves the issue, make a mental note. Remember the folder you renamed? Change it back to /wp-content/plugins/.

Now, head to your WordPress dashboard, specifically the left-hand sidebar — click Plugins. One by one, click deactivate on a plugin, then check whether the 503 error returns. When it does, note which plugin did the trick.

If you find a plugin is at fault and you can replace it, go ahead. If you’d rather keep the plugin, you do have an option: Control its resource usage.

Adjust resource usage

Some plugins use server resources inefficiently in the background. This gradual overload can eventually surpass limits and cause 503 crashes. Rather than delete useful WordPress plugins and lose their features entirely, first try installing a resource control plugin.

WP Rocket’s Heartbeat Control plugin caps how many background tasks — like autosaves and notifications — plugins can run simultaneously. Controlling background usage this way keeps helpful plugins running smoothly within reasonable constraints.

Find WP Rocket’s Heartbeat Control plugin in the WordPress plugin directory.

Based on your hosting plan’s resource allotment, set limits with WP Rocket, then see whether overload situations stop happening. If the control plugin fixes the 503 errors, the root cause was too many background jobs draining resources due to inefficient plugins.

Switch themes

You now know WordPress themes can contain bugs, bloat or errors can disrupt communication between servers and WordPress websites, prompting 503 warning messages. Switching to a lightweight default theme like Twenty Twenty-One can quickly reveal if your current theme files and templates are at fault.

A screenshot of the Twenty Twenty-One WordPress theme’s store page.

If the error message disappears after you swap themes, find a new lightweight theme for your website. Alternatively, you can check whether your previous theme customizations triggered a known bug. If so, you can try to work around it or wait for the bug to be patched.

Note that you can use staging websites to test options in your theme folder. Well-coded themes run smoothly without draining resources unnecessarily or preventing critical background processes from completing.

Enable debug mode

When server errors evade detection from manual troubleshooting, enable debug mode to pull back the curtains. This toggle sends detailed warnings whenever scripts fail or system exceptions occur. Read the results by using an FTP client and entering wp_debug_logs in the search bar.

Debug messages call out misbehaving plugins and themes, especially if tied to repetitively crashing processes that interfere with server resource access.

Debug logs can seem verbose or even gibberish to the average website owner. However, there’s a chance you can pinpoint whether software errors contribute or not.

If detectable patterns emerge in debug logs, experienced developers can translate their findings into action plans that tackle the weak points. If no red flag events appear, deeper infrastructure checks come next.

Check server logs

Hosting providers record detailed server activity logs that track every process and action occurring behind the scenes. These granular records are basically breadcrumb trails, which can reveal sequential issues that eventually snowball into service disruptions.

Gaining insight from server logs requires expertise. If you conduct the analysis yourself, here’s what to look for:

  • Traffic, especially unprecedented spikes in visitors
  • Storage usage approaching the limit
  • Database activity with too many simultaneous queries
  • Processing power maxing out on tasks

Restore from a backup

Restoring your website from a whole-site backup provides a fresh, clean slate for continuity. Automated daily or weekly backups capture software configurations and data — this lets you switch back to a fully functioning version of your website before whatever introduced the instability.

Bluehost clients using VPS hosting or dedicated hosting can easily configure backups and restore them.

Backup restorations practically turn back time, overwriting any corrupted files and rolling back untenable adjustments. This failsafe option wipes any problematic edits, additions or deletions that could be the cause of your 503 error.

If your 503 error persists after you attempt all the above general fixes and allow time for temporary spikes to clear, contact Bluehost’s 24/7 support team. We’ll dig deeper to troubleshoot the issue and clear up the error so your brand gets back on track.

Preventing future 503 errors

Once your WordPress 503 error is finally resolved and your website regains normal functionality, the best-case scenario is that it never happens again. If you’re proactive and employ preventative measures now, you won’t worry about this error in the future.

You can do a few things to avoid 503 errors popping up again:

How to prevent future 503 errors in WordPress.

Monitor performance

Keep consistent eyes on your website’s performance metrics weekly, even during healthy periods; fluctuations are often detectable before escalating into the danger zone.

Watch for gradual resource usage growth, creeping load times, low available storage space and spikes in concurrent visitors. Bump up your hosting plan for extra capacity and performance to avoid hitting your resource ceilings.

Stress test configuration

Stress testing, which is intentionally simulating traffic floods and load spikes, reveals whether your infrastructure can withstand and automatically recover from potential heavy usage.

By deliberately pushing established thresholds, you identify your website’s breaking point. If your website can’t handle the usage levels your brand aims to grow into soon, ask your hosting provider to tweak your server limits and resource allocation to widen safety margins.

Vet plugins and themes

Before you install new plugins and themes, carefully evaluate them based on reviews and ratings that mention their resource requirements. Test the plugins and themes on staging websites before going live.

Use security tools

Safeguards like firewalls and threat monitoring platforms will protect your website against malicious efforts to overload your infrastructure. By minimizing the threat of external disruptions, you knock off a variable in whether your website and host server stay running smoothly.

Final thoughts: How to fix WordPress 503 errors

While 503 errors disrupt both website access and audience trust, troubleshooting and preventative measures make resolution achievable without damage.

Now, you know how to methodically isolate the error’s root cause and address the issue from multiple angles.

Rather than leave troubleshooting responsibilities in your hands alone, move forward with better WordPress hosting featuring expert server management. Our experts are available 24/7 because your brand is on the line.

  • Minal Agarwal

    Minal is the Director of Brand Marketing at Bluehost. With over 15 years of business experience in the technology industry, she strives to create solutions and content that fulfill a customer's needs. She is a dog mom and a stickler for calendaring.

    Masters in Marketing Management
    Previous Experience
    Strategic Partnerships, Customer Success, Events and Community
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