What Is a 503 Service Unavailable Error?
A 503 Service Unavailable error occurs when a server receives a request but cannot process it at that time. The server is reachable, but it doesn’t have the capacity or availability to respond at the moment the request has been made and received.
What the 503 Service Unavailable Status Code Means
The 503 status code communicates unavailability that is temporary. This status code signals that this unavailability will be resolved without any changes being made to the requested URL. This status code tells crawlers that the server is unable to handle requests at the moment, but that it will recover.
What Causes a 503 Service Unavailable Error?
503 errors are caused by server overload, scheduled maintenance, exhausted resources, misconfigured infrastructure, upstream service failures, and other similarly related issues or events. No matter the case, the server intentionally declines the request rather than returning incorrect content.
Temporary 503 Errors vs Persistent 503 Errors
You’ll see temporary 503 errors during things like brief outages and system maintenance. Persistent 503 errors indicate unresolved infrastructure issues and can cause search engines to go through a reassessment of your website’s stability if this temporary error turns into a consistent signal being picked up by their crawlers.
Can 503 Errors Hurt SEO?
503 errors do not harm SEO ordinarily. When 503 errors continue past a certain point they can absolutely hurt your SEO though. But, when used intentionally and for a short period of time, search engines treat them as a signal to retry later. So as long as you’re intentionally using them and they only appear for a short window of time, you have nothing to worry about.
How to Resolve 503 Service Unavailable Errors
Resolving 503 errors depends on the reason the 503 exists in the first place. If you aren’t doing it for maintenance purposes, you’ll have to identify the reason it is occurring. 503 errors can be caused by capacity limits, server configuration issues, dependency issues, resource related issues and more. So, identifying and resolving your 503 errors will depend on any number of things unique to your website’s infrastructure. You will want to resolve the issues behind the error though, otherwise you will be in danger of persistent, or frequent errors.
When Using a 503 Status Code Is the Correct Choice
You want to use a 503 status code when you have planned maintenance, controlled downtime, short-term traffic spikes that will raise your infrastructures resource limit past what you have allotted for your budget. You may even employ this status code if you have other limits you want to be mindful of conserving as well.
How to Identify 503 Errors on Your Website
503 errors can be identified through server logs, uptime monitoring, crawl diagnostics, and search console coverage data. Though it is best to observe patterns over time as opposed to one-off events.
Final Thoughts on Managing 503 Errors for SEO
Much like all status codes, the 503 Service Unavailable status code is a powerful signal. Used correctly, it protects search visibility during downtime and can conserve rankings by communicating to crawlers that the unavailability is temporary. But, when used carelessly, it introduces uncertainty about site reliability, and can actually hurt rankings.
Hire Technical SEO Specialists to Resolve 503 Errors
Persistent availability issues require coordination between infrastructure, development, and SEO. If you want more stability in your website’s infrastructure, you need 503 errors resolved, or if you just want to improve your rankings, our seo experts can assist you however needed. Just head over to our page to see the comprehensive SEO services we offer. Or, you can even head over to our audit page to schedule your comprehensive SEO audit.