4xx Client errors
The request conflicts with the current state, for example a duplicate entry or an edit based on an old version.
Show the user what conflicts and let them reload or pick another value.
The first line of the response shows the status code; -L follows redirects and shows each step.
curl -I https://example.com/page
curl -IL https://example.com/old-pageThe request conflicts with the current state, for example a duplicate entry or an edit based on an old version.
Show the user what conflicts and let them reload or pick another value.
Return 409 yourself (abort(409, '…')) for duplicates the database unique index would otherwise reject with a 500.
Last updated: 7 November 2026. See the update log at the end."Which is faster, PostgreSQL or...
Last updated: 5 November 2026. See the update log at the end.In a normal PHP-FPM request,...
A slow Docker build usually has one of a few causes: you are sending far more...
We use cookies to improve your experience and analyze traffic. By continuing, you agree to our Privacy Policy.
