PKCE generator

Generate a verifier and its S256 challenge, or check an existing pair. All calculations stay in this tab.

BROWSER ONLY

code_verifier

43–128 unreserved characters. The generator uses 32 cryptographically random bytes.

Challenge to compare (optional)

Generate a new pair or calculate the challenge for your own verifier.

Use the pair

1. Send code_challenge and code_challenge_method=S256 in the authorization request.
2. Keep code_verifier in the client until the callback. Send it when exchanging the authorization code.
3. Generate a fresh verifier for every authorization request. The RFC example is public test data.

The calculation is BASE64URL(SHA256(ASCII(code_verifier))), without = padding. The built-in test vector is from RFC 7636 Appendix B.

Inputs exist only in this page's memory: no upload, URL sharing or browser storage. Copy only what you need before leaving or reloading the page.

Continue with the request builder or read Authorization Code + PKCE.