4xx Client error
HTTP 404 Not Found
The server has no current resource at this URL, or won’t say whether one exists. It doesn’t say whether the absence is temporary or permanent; 410 Gone says it is permanent.
Defined in RFC 9110, section 15.5.5(opens in a new tab)
//_01 Uptime checks
Is 404 up or down for a monitor?
Uptimecheck HTTP monitor
Default settings
Down. It is outside the default 200–399 range, so a monitor reports an outage once a second check confirms it. If 404 is the answer you expect from that URL, add it to the monitor’s expected status codes.
Is it down? checker
Free, at /is-it-down/
Up. The checker counts any answer below 500 as the site answering: a 404 comes from a server that is running.
//_02 Causes and fixes
Why you see 404 and what to do
Typical causes
- A page that was deleted or moved without a redirect.
- A typo in a link or URL.
- Rewrite rules that stopped working, such as WordPress permalinks after a server move, or files missing after a deploy.
If you run the site
- Redirect moved pages to their new URL with a 301.
- Fix internal links that point to missing pages, and keep a monitor on the pages that matter most.
- A custom “not found” page must still answer with status 404, not 200.
If you’re a visitor
- Check the URL for typos, or search the site for the page.
Know the moment your site stops answering as it should
An Uptimecheck monitor requests your page as often as every minute, checks the status code against the ones you expect, confirms a failure with a second check and then alerts you.
14-day free trial · No credit card required
Questions
What does HTTP 404 mean?
The server has no current resource at this URL, or won’t say whether one exists. It doesn’t say whether the absence is temporary or permanent; 410 Gone says it is permanent.
Does an uptime monitor count 404 as down?
Down. It is outside the default 200–399 range, so a monitor reports an outage once a second check confirms it. If 404 is the answer you expect from that URL, add it to the monitor’s expected status codes.
Downtime is obsolete.
Set up your first monitor in under a minute, or look around the live demo first.
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