Convert tools

JWT Generator and Signer

Create signed JWTs with HMAC, RSA, RSA-PSS or ECDSA using browser Web Crypto.

Convert in your browser · No sign-up

Supports HS/RS/PS/ES 256, 384 and 512. HS256/384/512 need at least 32/48/64 UTF-8 key bytes; RSA keys need 2048 bits. PEM uses PKCS#8 private keys.

Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.

How to use

  1. Create signed JWTs with HMAC, RSA, RSA-PSS or ECDSA using browser Web Crypto.
  2. Choose the mode or options, then run the tool.
  3. Review the result, then copy or download the TXT file.

Example

{"sub":"123"} + secret → signed JWS compact token

Details and limitations

Supports HS/RS/PS/ES 256, 384 and 512. HS256/384/512 need at least 32/48/64 UTF-8 key bytes; RSA keys need 2048 bits. PEM uses PKCS#8 private keys.

Text stays in your browser; it is not sent to a conversion server.

FAQ

JWT Generator and Signer — What are the supported inputs and limits?

Supports HS/RS/PS/ES 256, 384 and 512. HS256/384/512 need at least 32/48/64 UTF-8 key bytes; RSA keys need 2048 bits. PEM uses PKCS#8 private keys.

Format references

Tool page updated: