Critical Technical SEO
Client error (4xx)
- Severity
- Critical
- Impact
- High
- Effort to fix
- Low
- Issue code
http_4xx
Why it matters
The URL returns an error such as 404 Not Found. Visitors and crawlers reach a dead end and link equity is lost.
How to fix it
Restore the page, 301 redirect it to the most relevant live URL, or remove the links that point to it.
What this means
The URL returned a client error: most often 404 Not Found, sometimes 410 Gone, 403 Forbidden or 401 Unauthorized. The evidence shows the exact status.
The page was found through an internal link or the XML sitemap, so something on your site still points to it.
Why it matters
- Visitors who follow the link reach a dead end.
- Crawlers waste requests, and links into the URL pass no value.
- A 404 is normal for pages that truly no longer exist. The problem is linking to them.
What each status means
| Status | Meaning | Usual action |
|---|---|---|
| 404 | Not found | Redirect to a replacement, or remove the links |
| 410 | Gone on purpose | Fine for removed content; remove the links |
| 403 | Forbidden | Check bot protection or permissions; a public page should not return 403 |
| 401 | Login required | Expected for private areas; do not link to them from public pages or the sitemap |
How to fix it
- Find where the URL is linked: the URL details show the pages linking to it, and those pages are reported as Links to broken internal pages.
- If the page moved, add a 301 redirect to the new address and update the links.
- If it was removed on purpose with no replacement, remove the links and take it out of the sitemap. See Non-200 URL in XML sitemap.
- If it should exist, restore it.
If other websites link to the URL, fix it first: see Broken page with backlinks.
Verify the fix
Recrawl. Redirected URLs move to Redirecting URL, and URLs no longer linked from anywhere drop out of the crawl.
How it affects your score
Finding this issue on any page costs the Technical SEO score 8 points, plus up to 25 more depending on the share of crawled pages affected. As a critical issue type it also takes 3 points off overall site health (critical deductions stop at 15 points). Blocks indexing, breaks pages or loses traffic. Fix these first.
Find the affected URLs
Open Crawl > Issues and pick Client error (4xx). Each affected URL is listed with its evidence, and Copy URLs or Export URLs hands the list to a developer. The issue also appears in the Action Plan, ranked by impact (high) and effort (low), and in the issues CSV under the code http_4xx. After fixing, run a new audit and use Compare to confirm the URLs moved to fixed.