4xx Client error
HTTP 401 Unauthorized
The request lacks valid credentials for the resource. The server must send a WWW-Authenticate header saying how to authenticate. Despite the name it means “not authenticated”; a server that knows who you are but won’t let you in answers 403.
Defined in RFC 9110, section 15.5.2(opens in a new tab)
//_01 Uptime checks
Is 401 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 401 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 401 comes from a server that is running.
//_02 Causes and fixes
Why you see 401 and what to do
Typical causes
- A missing, expired or wrong API key or token.
- A wrong password for HTTP Basic authentication, such as a password-protected staging site.
If you run the site
- To monitor a protected URL, add the Authorization header to the monitor’s request headers.
- If the URL is supposed to ask for a login, add 401 to the monitor’s expected status codes instead.
If you’re a visitor
- Log in again; your session may have expired.
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 401 mean?
The request lacks valid credentials for the resource. The server must send a WWW-Authenticate header saying how to authenticate. Despite the name it means “not authenticated”; a server that knows who you are but won’t let you in answers 403.
Does an uptime monitor count 401 as down?
Down. It is outside the default 200–399 range, so a monitor reports an outage once a second check confirms it. If 401 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Downtime is obsolete.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.
14-day free trial · No credit card required