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Crypto & Hash

JWE Encrypt, Decrypt, and Protected Header Inspector

Encrypt and decrypt compact JWE tokens locally with dir/A256GCM or RSA-OAEP-256/A256GCM, and inspect protected headers without decrypting.

Free to use No sign-up Runs in your browser

Tool workspace

All JWE operations run locally in this browser tab. Plaintext, tokens, and keys are not uploaded or persisted. Avoid production secrets on untrusted devices.

Direct mode accepts a 256-bit oct JWK. RSA encryption accepts public JWK/SPKI PEM; RSA decryption requires a private JWK or unencrypted PKCS#8 PEM.

What is compact JWE?

JSON Web Encryption (JWE) protects content with authenticated encryption. Compact serialization has five dot-separated parts: protected header, encrypted key, initialization vector, ciphertext, and authentication tag. This tool deliberately supports a narrow modern profile: direct 256-bit symmetric keys with A256GCM, or RSA-OAEP-256 key wrapping with A256GCM content encryption.

How to encrypt, decrypt, or inspect a JWE

  1. 1Choose direct symmetric encryption or RSA-OAEP-256, then provide plaintext and the matching key.
  2. 2For direct mode, paste or generate a 32-byte oct JWK. For RSA encryption, provide a public RSA JWK or SPKI PEM.
  3. 3To decrypt, paste a compact JWE and the matching symmetric JWK or RSA private JWK/PKCS#8 PEM.
  4. 4Use header inspection to view alg, enc, kid, and other protected fields without supplying a key.
  5. 5Treat header-only results as unverified metadata until authenticated decryption succeeds.

Common JWE use cases

Testing an API encryption integration

Create interoperable compact JWE samples with explicit modern algorithms while debugging a service or client implementation.

Diagnosing a JWE configuration mismatch

Inspect protected alg, enc, and kid fields before decryption to identify a wrong key type or unsupported algorithm.

Verifying local decryption keys

Confirm that a symmetric JWK or RSA private key can authenticate and decrypt a known compact JWE without sending it to a third party.

Frequently asked questions

Can I trust a protected header inspected without decrypting?

No. Anyone can construct header-looking text. The header becomes authenticated only when decryption verifies the JWE authentication tag with the correct key.

Which algorithms are supported?

Only dir with A256GCM and RSA-OAEP-256 with A256GCM. Unsupported or legacy algorithms are rejected explicitly.

Are encrypted PEM private keys supported?

No. The browser import path used here supports unencrypted PKCS#8 PEM private keys. Encrypted PEM input is rejected rather than silently mishandled.