HTTP Status Codes: Ultimate SEO Guide

If you manage a website or are involved in digital marketing, understanding HTTP status codes is crucial. These codes play a significant role not just in website performance but also in Search Engine Optimisation (SEO). Without knowing how these codes work, you may face challenges in improving your site’s rankings and user experience.

This guide will explain what HTTP status codes are, why they matter for SEO, the most common types of status codes, and best practices to handle them effectively.

What Are HTTP Status Codes?

HTTP status codes are three-digit numbers that a web server sends back to a browser or search engine when it receives a request for a webpage. They tell the client (browser or bot) whether the request was successful, redirected, or if there was an error.

Each status code belongs to one of five categories, based on the first digit:

• 1xx – Informational: The request is being processed.
• 2xx – Success: The request was successful.
• 3xx – Redirection: Further action is needed to complete the request.
• 4xx – Client Error: The request has a problem from the client side.
• 5xx – Server Error: The server encountered an issue fulfilling the request.

Why Are HTTP Status Codes Important for SEO?

Search engines like Google crawl websites to index and rank pages. HTTP status codes help these bots understand how to treat each page. For example:

• If a page returns a 200 OK status, it means the page is accessible and can be indexed.
• If a page returns a 404 Not Found, it means the page doesn’t exist, so Google will eventually remove it from its index.
• If a page redirects with a 301 Moved Permanently, it passes most of its ranking power to the new URL.

Mismanagement of status codes can lead to loss of traffic, poor user experience, and ultimately lower rankings. For instance, broken pages returning 404 errors without any proper handling can harm SEO.

Common HTTP Status Codes Every SEO Should Know

Let’s discuss the most important HTTP status codes that directly affect SEO.

200 OK

• Meaning: The request succeeded and the content is returned.
• SEO Impact: This is the ideal status code for pages that are live and ready to be indexed. Googlebot and users both expect this for normal pages.

301 Moved Permanently

• Meaning: The requested URL has been permanently moved to a new location.
• SEO Impact: This code tells search engines to transfer the link equity (ranking power) from the old URL to the new one. It’s the preferred method to handle URL changes or site restructuring.

302 Found (Temporary Redirect)

• Meaning: The URL is temporarily redirected to another page.
• SEO Impact: Unlike 301, 302 does not pass full link equity. If used improperly, it can cause search engines to keep the old page indexed, which might dilute SEO efforts.

404 Not Found

• Meaning: The server cannot find the requested page.
• SEO Impact: When users or bots hit a 404 page, it means the content is missing. If a page was previously indexed and now returns 404, Google will remove it over time. Frequent 404 errors can negatively affect your site’s SEO.

410 Gone

• Meaning: The requested page is permanently removed.
• SEO Impact: This status is more definitive than 404. It tells search engines that the page is intentionally gone and should be removed from the index quickly.

500 Internal Server Error

• Meaning: The server encountered an unexpected condition.
• SEO Impact: This is a serious error affecting both users and bots. If your site returns 500 errors frequently, it will hurt crawlability and rankings.

503 Service Unavailable

• Meaning: The server is temporarily unavailable.
• SEO Impact: This code tells search engines that your site is down temporarily. It’s useful during maintenance but should not last long. Extended 503 errors can lead to loss of ranking.

How HTTP Status Codes Affect Crawling and Indexing

Search engines use crawlers (like Googlebot) to visit your website pages. The HTTP status codes returned influence how these crawlers behave.

• 2xx (Success) codes: The crawler indexes the page normally.
• 3xx (Redirect) codes: The crawler follows the redirect. A 301 passes link equity to the new URL; a 302 may or may not.
• 4xx (Client error) codes: The crawler assumes the page is missing or inaccessible.
• 5xx (Server error) codes: The crawler will retry later but may stop crawling if errors persist.

If many pages on your site return errors, crawlers may reduce crawl frequency, which slows down new content indexing or ranking updates.

Best Practices for Handling HTTP Status Codes for SEO

1. Use 301 Redirects for Permanent URL Changes

If you move or rename pages, use a 301 redirect from the old URL to the new one. This ensures the link authority is preserved and users do not land on broken pages.

2. Avoid Using 302 Redirects for Permanent Moves

Use 302 redirects only when you intend the change to be temporary. Otherwise, Google may not transfer link equity, causing SEO loss.

3. Fix Broken Links and Reduce 404 Errors

Regularly audit your website for broken links. Use tools like Google Search Console or Screaming Frog to identify URLs returning 404 errors. Fix these by restoring the content, redirecting to a relevant page, or customising your 404 page to help users navigate.

4. Custom 404 Pages Enhance User Experience

Design a helpful 404 error page with links to popular content or a search box. This keeps users engaged rather than bouncing away, indirectly benefiting SEO by improving user signals.

5. Use 410 Status Code for Removed Content

If you permanently delete a page and don’t want it replaced, use a 410 Gone status. This speeds up removal from search engines compared to a 404.

6. Handle Server Errors Quickly

Monitor your site for 5xx errors and fix server issues immediately. Prolonged server errors hurt your crawl budget and can reduce rankings.

7. Use 503 During Site Maintenance

When performing site maintenance, serve a 503 Service Unavailable status with a “Retry-After” header to indicate downtime duration. This signals search engines not to penalise temporary unavailability.

Tools to Check HTTP Status Codes

Several tools can help you check and monitor HTTP status codes:

• Google Search Console: Shows crawl errors and indexing issues.
• Screaming Frog SEO Spider: Crawls your site to report status codes.
• HTTP Status Code Checker websites: Quickly test URLs.
• Browser Developer Tools: Inspect network tab to see HTTP responses.

Regularly checking status codes helps maintain site health and improve SEO performance.

Impact of HTTP Status Codes on User Experience

Apart from SEO, HTTP status codes impact user experience (UX).

• 200 OK pages load smoothly.
• Redirects if well-managed, can guide users seamlessly.
• Broken pages (404, 410) frustrate users and increase bounce rates.
• Server errors (500, 503) make your site unreliable.

Google considers user experience as a ranking factor. A site with fewer errors and smooth navigation tends to rank better.

Special Considerations for HTTP Status Codes and SEO

Pagination and Canonical Tags

Sometimes, paginated content returns 200 OK status but has duplicate content issues. Use canonical tags or rel=”next” and rel=”prev” attributes to tell search engines the relationship between paginated pages.

HTTPS and Redirects

If you have migrated your site from HTTP to HTTPS, use 301 redirects to point all HTTP pages to their HTTPS counterparts. This avoids duplicate content issues and improves security, which is a ranking factor.

Mobile vs Desktop URLs

If you have separate mobile and desktop URLs, ensure redirects and status codes are set correctly to avoid SEO confusion.

Common Mistakes to Avoid

• Using 302 redirects instead of 301 for permanent moves.
• Ignoring broken links and 404 errors.
• Redirect chains and loops: Avoid multiple redirects in a chain, which slow down crawling.
• Using 200 status for error pages instead of proper 404 or 410.
• Not using 503 during maintenance leading to search engines indexing error pages.

Summary

HTTP status codes might seem technical, but they are fundamental to your website’s SEO success. Proper understanding and management of these codes ensure search engines can crawl, index, and rank your site effectively.

Here are the key takeaways:

• Always aim for 200 OK status on live pages.
• Use 301 redirects for permanent URL changes.
• Avoid broken pages; fix or redirect 404 errors.
• Use 410 Gone for permanently deleted pages.
• Handle server errors promptly to maintain crawlability.
• Use 503 Service Unavailable for planned downtime.
• Monitor your site regularly with SEO tools.

With correct handling of HTTP status codes, you improve not only your website’s SEO but also the overall user experience, which is equally important in today’s competitive digital landscape.