oauth2.dev
End-to-end OAuth 2.0 and OpenID Connect debugging

Debug OAuth and OIDC flows faster.

Validate discovery documents, launch real browser flows, inspect callbacks, probe token endpoints, and debug returned tokens in one focused workbench.

OpenID config validationCallback inspectionToken endpoint testingJWT debugging

A better default workflow

Real flow coverage

Stop stitching together five different sites just to answer one protocol question.

Flow
DiscoveryAuthorizeCallbackTokenDebug
Discovery checks
issuervalid
jwks_urivalid
userinfowarning
Callback snapshot
response_mode=form_post
code=SplxlOBeZQQYb...
state=7h5C9d0Y1l...

Hosted Mock IdPs are available when you need a controlled issuer for deeper testing, but the main experience is faster protocol debugging and validation.

Recommended Workflow

Follow the flow instead of guessing.

oauth2.dev is strongest when you use the tools as a chain: validate the provider, run the browser flow, inspect the callback, test the token exchange, then verify what the token actually contains.

1. Start with discovery

OpenID Configuration Validator

Fetch the issuer metadata, verify required fields, and surface endpoint issues before the browser flow starts.

2. Launch the browser flow

Authorization Flow Tester

Run a real authorization request with PKCE, response modes, and callback handling instead of relying on synthetic checks alone.

3. Exchange the code

Token Endpoint Tester

Probe token endpoint behavior, OAuth error semantics, content types, cache-control, and browser-facing CORS details.

4. Inspect the result

Token Debugger

Decode the returned token, verify signatures, inspect claims, and confirm the identity data your client actually received.

Core Tools

Purpose-built for protocol work.

The newest surfaces are designed for real OAuth and OIDC flow debugging, not just isolated document checks.

Authorization Flow Tester

Discover authorization endpoints, launch the real browser flow, and inspect the callback returned to oauth2.dev.

Token Endpoint Tester

Probe token endpoints with form-encoded requests and inspect content type, OAuth error formatting, cache-control, and CORS behavior.

OpenID Configuration Validator

Validate an OpenID Connect discovery document from an issuer URL and surface configuration issues, missing claims, and endpoint problems.

JWKS Endpoint Validator

Fetch a JWKS document, validate key material, and check for common endpoint and key-shape problems before they hit production.

UserInfo Endpoint Validator

Check HTTPS, reachability, response semantics, and browser access behavior with optional bearer token probes.

Token Debugger

Decode and inspect tokens, verify signatures, and validate claims when troubleshooting OAuth 2.0 and OpenID Connect flows.

When you need a controlled issuer

oauth2.dev also includes hosted Mock IdPs for deeper test environments, but that is a supporting capability rather than the homepage headline.

Custom users and claims

Create mock users, attach custom claims, and see how your client behaves with realistic identity data.

Managed keys and JWKS

Generate or import signing keys, expose JWKS, and debug the issuer behavior alongside the validator tools.

Logs and replay

Review recent IdP requests and replay common authorization patterns from the dashboard debug console.

Why oauth2.dev

Clearer than scattered tools, deeper than a single mock issuer.

One place for the protocol lifecycle

Move from discovery to browser flow, callback inspection, token exchange, key validation, and token debugging without tab-hopping between unrelated tools.

Built for real OAuth behavior

The strongest tools are the ones that exercise actual browser redirects, endpoint semantics, and returned parameters instead of just checking static JSON.

Privacy-respecting by default

Some tools run fully in the browser. Others make server-side requests so oauth2.dev can fetch or validate remote endpoints. We collect lightweight operational metrics to keep the service working and improve it.

See the privacy policy for details on server-side validation, operational telemetry, and data handling.

Start Here

Use the right tool first, then follow the flow.

If you are debugging a provider, start with discovery. If you are debugging a client, start with the authorization flow. If you already have a token, go straight to the debugger.