OAuth2 PKCE Generator
OAuth2 PKCE Generator: Generates cryptographically random URL-safe verifier, computes SHA-256 hash, and Base64URL encodes to create S256 challenge.
About this oauth2 pkce generator
Generates cryptographically random URL-safe verifier, computes SHA-256 hash, and Base64URL encodes to create S256 challenge Validates and converts interface schemas client-side without transmitting private endpoint specifications.
API contract & interface schema logic
Uses a supplied valid verifier, or generates a random verifier when none is supplied, then computes its SHA-256 Base64URL S256 challenge
Worked schema conversion scenario
Scenario: A developer checks the RFC 7636 S256 challenge for a supplied code verifier.
Sample input:
Processing: Uses the supplied verifier, computes SHA-256, and Base64URL-encodes the S256 challenge; this example does not generate randomness.
Illustrative output:
Schema version & syntax constraints
Only empty input generates a 32-random-byte Base64URL verifier. A supplied verifier shorter than 43 characters, longer than 128 characters, or containing characters outside A–Z, a–z, 0–9, hyphen, dot, underscore and tilde is rejected; it is not replaced or truncated. This page generates S256 only and does not bind the verifier to an authorization transaction.
API specifications and schema models in OAuth2 PKCE Generator reflect OpenAPI and JSON Schema standards. Verify generated schemas against your runtime validator.
Client-side schema processing boundary
Schema analysis and protocol mapping in OAuth2 PKCE Generator execute locally in the browser tab without uploading endpoint definitions.
OpenAPI Specification & JSON Schema standards
OpenAPI Specification standards and JSON Schema draft definitions:
- RFC 6749 (The OAuth 2.0 Authorization Framework)
- RFC 7636 (Proof Key for Code Exchange by OAuth Public Clients - PKCE)
OAuth2 PKCE Generator verification · Audit standards
How to use it
- Enter a valid 43–128-character code verifier, or leave the input empty to generate one randomly.
- Compute SHA-256 over the selected verifier and Base64URL-encode the S256 challenge.
- Copy the verifier, challenge and method JSON.
Frequently asked questions
How does OAuth 2 PKCE Generator create values?+
It accepts a supplied 43–128-character RFC 7636 unreserved code_verifier from text or JSON. Only empty input generates 32 random browser bytes encoded as Base64URL; a supplied invalid verifier is rejected. Web Crypto SHA-256 and Base64URL produce the S256 challenge.
Can you show an input and its result?+
The RFC-style verifier dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk produced its independently calculated base64url SHA-256 challenge and code_challenge_method S256 in the browser.
Which PKCE inputs and limits matter?+
Only S256 is emitted. A supplied verifier outside 43–128 characters or with disallowed characters is rejected, not replaced or truncated. The page does not store client registration or bind a verifier to an authorization transaction.
Does generating PKCE complete OAuth authorization?+
No. It does not contact an authorization server, create state, select redirect handling, exchange an authorization code, validate issuer metadata, or protect values after the page session.