Encryption & Keys Tools

Free online encryption tools — AES-256 file encryption, key generation and certificate utilities, all running client-side with the Web Crypto API.

6 tools

AES File Encryptor

Encrypt or decrypt any file with a passphrase using AES-256-GCM and PBKDF2 key derivation, entirely in your browser. Nothing is uploaded.

RSA Key Generator

Generate RSA key pairs (2048, 3072, 4096-bit) for encryption (OAEP) or signing (PSS) in PEM format using WebCrypto. Download or copy instantly.

ECDSA Key Generator

Generate ECDSA or ECDH key pairs on P-256, P-384, or P-521 in PEM or JWK format using WebCrypto. Private key blurred by default. Nothing uploaded.

Cert Decoder

Paste a PEM certificate and read its subject, issuer, validity dates, SANs, key algorithm and SHA-256 fingerprint. Decoded in your browser only.

CSR Generator

Generate a PKCS#10 CSR and matching private key in your browser. Supports RSA 2048/4096 and EC P-256/P-384. Nothing is uploaded or transmitted.

Also in Encryption & Keys

Tools from other categories tagged with Encryption & Keys

Text Cipher

Encrypt and decrypt text using Caesar cipher, ROT13, Atbash, and Vigenère cipher. Includes adjustable shift, custom keyword, and instant swap.

Why These Tools

AES-256 File Encryptor / Decryptor exists because handing a sensitive file to a browser-based converter usually means handing it to that converter's server first. This one derives a 256-bit key from your passphrase with PBKDF2, run 250,000 times over, then encrypts with AES-GCM so a wrong passphrase produces a clear failure instead of silently garbled bytes. RSA Key Pair Generator and ECDSA / ECDH Key Pair Generator both use the same WebCrypto approach: entropy from crypto.getRandomValues, private keys blurred by default, nothing transmitted. Between them they cover the two main asymmetric families — RSA for legacy compatibility and elliptic curve for modern TLS, JWT and code-signing work. A CSR builder and a certificate decoder come next.