Okuzeka
Software Engineering vocabulary · Release and Maintenance

Feature flag

Meaning in software engineering, with examples

nounCommon term

In software engineering, feature flag means: A setting that turns a feature on or off without deploying new code, so it can be shown to some users, tested in production or switched off quickly.

In Turkish: özellik bayrağı, feature flag, özellik anahtarı

How it is used

Also called a feature toggle. Code is shipped 'behind a feature flag' and the flag is later 'turned on' or 'flipped'. Old flags that nobody removes become technical debt. LaunchDarkly and Unleash are common tools.

Example sentences

  1. The new checkout is already in production behind a feature flag; we'll turn it on for staff first.

  2. When errors started, we just switched off the feature flag instead of doing a rollback.

Common collocations

  • behind a feature flag
  • turn on a feature flag
  • flip a flag
  • feature toggle
  • canary releaseReleasing a new version to a small share of users or servers first, watching its metrics, and only then rolling it out to everyone.
  • roll outTo release a new version, feature or change to users or servers, often step by step over a period of time rather than all at once.
  • deployTo put a new version of software onto servers or devices so that it starts running there, for example in a test environment or for real users.
  • continuous deliveryThe practice of keeping code always ready to release, so that any tested version can go to production at the push of a button.
  • roll backTo return a system to an earlier working version after a release or change causes problems.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Release and Maintenance

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: