5xx Server error
HTTP 505 HTTP Version Not Supported
The server doesn’t support, or refuses to support, the major version of HTTP used in the request.
Defined in RFC 9110, section 15.6.6(opens in a new tab)
//_01 Uptime checks
Is 505 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 505 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/
Down. A 5xx means the server, or something in front of it, failed to answer.
//_02 Causes and fixes
Why you see 505 and what to do
Typical causes
- A client using a version of HTTP the server or a proxy doesn’t handle.
If you run the site
- Check the protocol settings of the server and any proxy in front of it.
If you’re a visitor
- Update your browser or app.
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.
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Questions
What does HTTP 505 mean?
The server doesn’t support, or refuses to support, the major version of HTTP used in the request.
Does an uptime monitor count 505 as down?
Down. It is outside the default 200–399 range, so a monitor reports an outage once a second check confirms it. If 505 is the answer you expect from that URL, add it to the monitor’s expected status codes.
Downtime is obsolete.
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