Cryptography tools
Cryptography protects data from being read (confidentiality) or modified (integrity) by anyone without the right key. These tools run entirely in your browser using the Web Crypto API.
AES
DES
ChaCha20
RC4
SPECK
XXTEA
RSA
RSA Key Generator
Generate an RSA key pair and export as PEM.
RSA Sign
Sign a message with an RSA private key (PSS or PKCS#1 v1.5).
RSA Verify
Verify an RSA signature with a public key.
RSA Encrypt
Encrypt text with an RSA public key (RSA-OAEP SHA-256) in your browser.
RSA Decrypt
Decrypt text with an RSA private key (RSA-OAEP SHA-256) in your browser.
ECDSA
EdDSA
SM2
SM2 Key Generator
Generate an SM2 elliptic curve key pair (Chinese national standard).
SM2 Sign
Sign a message with an SM2 private key (Chinese national standard).
SM2 Verify
Verify an SM2 signature against a message and public key.
SM2 Encrypt
Encrypt text with an SM2 public key (Chinese national standard).
SM2 Decrypt
Decrypt SM2 ciphertext with a private key (Chinese national standard).
SM4
JWT
JWT Decoder
Decode and inspect JSON Web Tokens (header, payload, signature).
JWT Sign
Create and sign JSON Web Tokens with HS256, HS384, HS512, RS256, RS384, RS512, PS256, PS384, PS512, ES256, ES384, or ES512.
JWT Verify
Verify a JWT signature against an HMAC secret, PEM public key, or JWK. Reports signature and claim validity separately.
JWE
About cryptography tools
Symmetric ciphers use the same key to encrypt and decrypt. AES is the standard for bulk encryption and comes in 128, 192, and 256-bit key sizes with modes like CBC, CTR, and GCM. ChaCha20 is a modern alternative designed for environments without AES hardware acceleration.
Asymmetric cryptography uses a key pair: a public key anyone can see, and a private key only you hold. RSA and ECDSA are used to sign messages and to encrypt keys during a handshake. Elliptic-curve algorithms achieve the same security with much smaller keys.
These tools do not replace a proper library. If you are building production software, use the Web Crypto API directly, or a well-reviewed library such as libsodium. The browser tools here are for exploring and verifying what production code should produce.