Refresh Token — What It Is

Enterno.io Editorial Team

What is a Refresh Token

By Anatoly Oshmanovsky · Updated Apr 17, 2026

Key idea:

Refresh token — a long-lived token (weeks/months) the client uses to obtain new short-lived access tokens without re-authenticating. Typical flow: access_token lives 15 min, refresh_token 30 days. When access expires, the client POSTs the refresh to the token endpoint → gets a new access. Critical: keep refresh in secure storage (httpOnly cookie, not localStorage).

Below: details, example, related terms, FAQ.

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Details

Access token: short-lived (5-15 min), sent on every request
Refresh token: long-lived (30+ days), only to token endpoint
Rotation: on refresh use, a new refresh is issued and old is revoked
Revocation list: Redis/DB with invalidated tokens
Grace period: 30 sec for race conditions on concurrent refreshes

Example

POST /oauth/token
  grant_type=refresh_token
  refresh_token=XXX
  client_id=Y
→ { access_token: "...", refresh_token: "NEW", expires_in: 900 }

Related Terms

HeadersCSP, HSTS, X-Frame-Options, etc.

SSL/TLSEncryption and certificate

ConfigurationServer settings and leaks

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How-to

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Alternatives

Frequently Asked Questions

Where to store a refresh token?

Server-side: session/database. Client-side: httpOnly + Secure + SameSite=Strict cookie. Never localStorage — XSS risk.

What to do on suspected leak?

Revoke all refresh tokens for the user via <code>DELETE /tokens WHERE user_id=X</code>. User must relogin.

Refresh rotation — required?

Best practice. Especially for SPAs. OAuth 2.1 draft mandates rotation.