Decode JWT tokens, verify HMAC signatures, and generate HS256, HS384, or HS512 tokens in one simple page.
A JWT has three Base64URL parts separated by dots: header, payload, and signature. This decoder formats the JSON parts and shows common claims.
How to use
1. Paste a JWT into the decoder to view its header, payload, signature, and common claims. 2. Enter the matching HMAC secret and click Verify to check HS256, HS384, or HS512 signatures. 3. Use Load decoded data if you want to copy the decoded header and payload into the generator. 4. Edit the Header JSON and Payload JSON, choose an algorithm, enter a secret, and click Generate JWT.About This JWT Tool
This JWT tool is designed for quick development and debugging. It supports Base64URL JWT decoding and HMAC-based JWT signing and verification.• Features
JWT Decoder: Decode the header and payload JSON from a JWT token and view the three token parts clearly by line. Claims Summary: Quickly check common claims such as subject, issued-at time, expiration time, and token time status. Signature Verification: Verify whether an HS256, HS384, or HS512 token signature matches a secret. JWT Generator: Create a signed HMAC JWT from editable Header JSON and Payload JSON. Load Decoded Data: Move the decoded header and payload into the generator so you can edit and generate a new token. Quick Time Buttons: Set iat to the current Unix time or extend exp by 15 minutes, 1 hour, or 1 day. Copy Results Quickly: Copy the token, JWT parts, or generated JWT directly from the page. Browser-Based Processing: JWT decoding, generation, and signature verification are performed directly in your browser.• Notes
This tool supports HMAC JWT algorithms HS256, HS384, and HS512 for generation and verification. Tokens using RSA, ECDSA, EdDSA, or other algorithms can still be decoded, but their signatures are not verified by this page. The exp, iat, and nbf claims are Unix timestamps in seconds. The claim summary shows these timestamps as your browser's local date and time. :wiki_link