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How a 5xx Server Error Can Hurt Your Website's Rankings

Written by Ben Graves | Jun 7, 2016 2:00:16 PM

Following more recent Google updates throughout the years, server errors are increasingly detrimental for website rankings. If your website experiences any of these errors, it’s important for webmasters to take care of them before they become even worse issues. 404 page errors might be easily fixed with a custom 404 page or 301 redirect, but a 5xx server error is a different beast. There are two main server errors that people should look out for and fix.

5xx responses, particularly 500 Internal Server Errors and 503 Service Unavailable Errors, become bigger problems for websites in early 2015, as a fresh index came about. If Google comes across a website with a 500 response, the page will immediately stop ranking. However, there have to be multiple instances of 503 responses over a week or two before ranking stops and the page is removed from Google’s index.

Here are a few specific ways Google reacts to server errors and how to avoid these errors altogether, based on experiences that columnist Austin Blais and his team encountered and shared with Search Engine Land.

Intermittent 500 Internal Server Errors

Blais and his team found that one URL had a tendency to return 200 Success responses along with occasional 500 Internal Server Errors. This was because of an instable server, and crawl stats declined as a result. This server instability and the subsequent 500 errors caused the domain to drop in Google rankings.

The developers determined that the cause for the server instability was the implementation of a JavaScript-developed Single Page Application (SPA). As Google attempted to crawl multiple files and/or URLs in the SPA at one time, this could have caused the server to fail occasionally. All in all, the issue caused 2,122 keywords to drop from the top 10 spots in Google rankings and 2,959 dipped from 11-20 spots to below the 20th spot. The changes took place within a week, but everything returned to normal once the server errors stopped.

In the end, this experience revealed the kind of temporary hassle that users of Angular JavaScript SPAs are likely to have, and which is something for which developers need to prepare before implementing.

500 Responses Resulting in Downtime

A specific type of page on the Blais’s team’s domain experienced 500 Internal Server Errors, which caught Google’s eye for around 18 hours. The amount of time each page returned this response is unclear, but the overall impact it had was bad enough.

The drop in keyword rankings was sporadic, resulting in drops of anywhere from five to 100 positions for all 239 tracked keywords. New rankings weren’t as low if Google could find other pages on the domain that were relevant to the search query. Blais’s team used BrightEdge to track the keywords and observe Google’s behavior throughout the 18-hour downtime.

The most interesting thing to note from this experience is that Google actually ranked pages that weren’t exactly what people would search for with certain queries, and Blais’s team couldn’t quite understand that behavior either.

Long Periods of 503 Service Unavailable Responses


Blais’s team of developers found that a domain returned occasional 503 Service Unavailable responses for a period of three months. Once again a JavaScript SPA was responsible, as timeouts occurred when the server couldn’t support multiple requests. Google Search Console (GSC) reported these responses, and about 1,000 keywords fell off of page one in Google when 503 error instances went up from an average of 3,000 to 25,000-30,000.

What the developers learned from this experience was that Google is more likely to punish websites that have 503 errors over a longer stretch of time than those that experience them for shorter periods.

How to Avoid Keyword Ranking Drops Through a 5xx Server Error

While it may take a little while for 503 server errors to result in dropped rankings, 500 Internal Server Errors have an immediate negative effect. Websites should make sure that if they do experience 500 errors, they are able to fix them before Google can have a chance to negatively impact your site. If a 503 response occurs, there’s a better chance of websites avoiding negative ranking impact if they can take care of it before it goes on for too long. Thankfully, it doesn’t take too long for Google to restore website rankings once server issues are resolved.

It appears that there is a fresh index that works on a page-by-page basis, and it is directly associated with a recently released Mobile Algorithm Update. This is good for domains, as it helps to ensure that they don’t completely drop off in Google rankings as long as there are pages relevant to the keyword.

Engineers should consider the overall load that SPAs will be able to support before implementing them. If multiple server-side rewrites are inevitable, server errors may occur. Identifying and correcting a 5xx server error in time can also prevent major negative effects on rankings.

If you want to prevent this fresh index from hurting your website, you should have a team of developers who know how to effectively handle 5xx server errors along with other potential issues. If you can avoid server errors and other common development problems, coupled with good SEO and PPC practices, your website should perform well on Google across the board.