Free Online Hash and Security Tools
Hashing and inspection: MD5, the SHA family, bcrypt, argon2, HMAC signatures, JWT decoding, password strength estimation. Here the browser-only design is not a convenience, it is the requirement — a secret you paste into a page that posts it somewhere is a secret you now have to rotate. Worth keeping in mind while you work: MD5 and SHA-1 are still fine for checksums and unsuitable for storing passwords.
Tools in this category
- Password Strength Checker Test how strong a password is in your browser with a live strength meter, entropy in bits, character-set analysis, and tips to make it stronger.
- Argon2 Hash Generator Generate Argon2id, Argon2i, and Argon2d password hashes in your browser with tunable iterations, memory cost, parallelism, and hash length, and copy the standard PHC-encoded string.
- HMAC Generator Generate an HMAC (hash-based message authentication code) from a message and secret key using SHA-256, SHA-1, SHA-384, or SHA-512. Output the HMAC as lowercase hex and Base64, fully client-side in your browser.
- JWT Validator Paste a JWT to verify its signature and validate its claims. Verify HMAC signatures (HS256, HS384, HS512) against a secret you supply, check exp, nbf, and iat with human-readable times, and optionally match aud and iss. Everything runs client-side in your browser.
- API Key Generator Generate secure, random API keys in your browser. Pick a key prefix (sk_, pk_, api_, or your own), choose an alphanumeric, hex, or base64url format, set the length and how many keys to create, and get cryptographically random keys built with the Web Crypto API. Nothing is uploaded.