bearer token
compound.compound. a digital key that gives access to a computer system or website. Anyone who has this key can use it, so you must keep it very safe.
compound. a security credential that grants access to a protected resource to any party in possession of it. It functions on the principle that the holder (the bearer) is authorized, requiring no further cryptographic proof or identification.
The app uses a bearer token to log you in automatically.
When you log into the API, the server sends back a bearer token that your browser must include in every future request.
Security protocols for bearer tokens must be rigorous, as the lack of a secondary authentication factor means that any intercepted token can be used by an attacker to impersonate the legitimate user.
A compound of the Middle English 'berere', denoting one who carries or possesses something, and 'token', from the Old English 'tācen', meaning a sign or symbol. The construction mirrors the legal concept of a bearer instrument, which entitles the physical holder to the value specified.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often used in the context of OAuth 2.0 and web development; frequently paired with the 'Authorization' header.
Last updated July 22, 2026