Deprecated means that a feature is still present and working but is officially discouraged and expected to be removed in a future release. It is a warning to stop using it and move to the recommended alternative.
Why it matters
Software needs a way to evolve without breaking everyone at once. Deprecation gives users time to migrate before removal, usually announced in release notes and often through warnings in logs. Ignoring these warnings turns into urgent work later, when an upgrade finally removes the feature. Under semantic versioning, removal normally waits for a major release.
Example
Warning: mysql_connect(): The mysql extension is deprecated
and will be removed in the future: use mysqli or PDO insteadIn an API, a response header such as Deprecation or Sunset may indicate the date after which an endpoint stops working, so clients can plan.
Common mistakes
- Treating deprecation warnings as noise and hiding them instead of scheduling the fix.
- Deprecating a feature without naming the replacement or a removal timeline.
- Assuming deprecated means already broken; it usually keeps working until removal.
Related
Get notified when this term updates
Plus occasional practical tips on uptime and monitoring, nothing else. Unsubscribe anytime.
This page is general information written by our editorial team and updated when documentation changes. Servers and providers differ, so test changes safely first. See our editorial policy and disclaimer.