5xx Server error Non-standard · used by Cloudflare
HTTP 526 Invalid SSL Certificate
A Cloudflare code: with SSL set to Full (strict), Cloudflare couldn’t validate the origin server’s certificate, so it refused to connect.
Documented in Cloudflare: 5xx errors(opens in a new tab)
//_01 Uptime checks
Is 526 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 526 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 526 and what to do
Typical causes
- An expired or self-signed certificate on the origin.
- A certificate that doesn’t cover the host name, or a missing intermediate certificate.
If you run the site
- Renew or replace the origin’s certificate; a Cloudflare Origin CA certificate also works in Full (strict).
- Check the certificate with an SSL checker against the origin directly.
If you’re a visitor
- Try again later; the site’s certificate needs fixing.
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 526 mean?
A Cloudflare code: with SSL set to Full (strict), Cloudflare couldn’t validate the origin server’s certificate, so it refused to connect.
Does an uptime monitor count 526 as down?
Down. It is outside the default 200–399 range, so a monitor reports an outage once a second check confirms it. If 526 is the answer you expect from that URL, add it to the monitor’s expected status codes.
Related status codes
All status codesDowntime is obsolete.
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