Hasher

Hasher is a developer's toolbox in a popup: hashes, HMAC, checksums, ciphers, passwords, JWT, JSON, diffs and everyday conversions. Privacy: everything is computed locally in your browser. The extension makes no network requests and collects nothing — no analytics, no telemetry, no accounts. What you type stays in the popup. The only permission it asks for is writing to the clipboard when you click a result. Hash: SHA-256, SHA-512, SHA-1, MD5, SHA-3 (256, 512), Keccak-256, SHA-384, SHA-224, RIPEMD-160, BLAKE2b (256, 512), SRI string for <script integrity> HMAC: SHA-256, SHA-1, SHA-512, SHA-384, MD5 CRC: CRC-32, CRC-32C, CRC-16 (MODBUS, CCITT-FALSE, XMODEM), CRC-8, CRC-64/XZ, Adler-32 Password: Passphrases from the EFF wordlist and random passwords with the entropy estimate; random keys in hex and Base64 UUID: Generate UUID v4, v7 and ULID; inspect a pasted UUID / ULID (version, variant, embedded time); UUID v5 from a name Cipher: AES-256-CBC with a passphrase, byte-compatible with openssl enc -aes-256-cbc -pbkdf2 (and the legacy -md md5 format) IP: IPv4 and IPv6 — canonical form, decimal, hex, binary, PTR record, address type; subnet calculator (network, netmask, first / last host, broadcast, hosts) URL: Scheme, host (IDN in Unicode), port, path, decoded query parameters, fragment, credentials, origin, normalized form Time: Unix time (seconds or milliseconds) ↔ ISO 8601, RFC-1123, UTC and local datetime, with the weekday, ISO week and day of the year; durations both ways (90061 → 1d 1h 1m 1s, "1h 30m" → seconds) Numbers: Decimal, hex, octal, binary, Roman, IEEE-754 double / single — any base in, the others out, arbitrary size Strings: Length in characters, bytes, words and lines; UTF-8 / UTF-16 ↔ Hex, code points; case conversions (camelCase, snake_case, kebab-case, Title Case, slug…) JWT: Decode header and payload, claims with expiry in local time; verify HS256 / 384 / 512 with a secret, RS / PS / ES / EdDSA with a PEM or JWK public key; sign a payload with HS256 Encode: Base64 / Base64url, Base32, Base58 (encode and decode), encodeURI(), encodeURIComponent(), HTML special chars, ROT13 Cron: Schedule builder ↔ crontab expression, plain-English description, the next 5 runs; six-field expressions with seconds JSON: Pretty-print, minify, convert to YAML (optionally with sorted keys), quote as a JSON string, syntax errors with the position Diff: Two texts side by side, compared line by line with the changed characters highlighted; ignore whitespace / case Usage: enter text and click a result — it is copied to the clipboard. The last tab is remembered; Alt+1…9 switch tabs. Light and dark themes follow your system, or pick one. The extension can be opened in a separate tab for more room. Version 2.2: URL and IP tabs, JWT verification with public keys, JSON → YAML, calendar hints and durations on the Time tab, cron with seconds, Base64url / Base32 / Base58, case conversions. Open source (MIT): https://github.com/s12v/hasher