A developer's toolbox: hashes, ciphers and everyday conversions. Everything is computed locally in the popup — nothing leaves your browser.

Privacy: the extension makes no network requests and collects nothing — no analytics, no telemetry, no accounts. What you type stays in this window and is gone when you close it (only the chosen tab and theme are remembered). The single permission it asks for is writing to the clipboard when you click a result. Privacy policy.

• Hash SHA-256, SHA-512, SHA-1, MD5, SHA-3 (256, 512), Keccak-256, SHA-384, SHA-224, RIPEMD-160, BLAKE2b (256, 512), SRI for <script integrity>
• HMAC SHA-256, SHA-1, SHA-512, SHA-384, MD5 — webhook signatures, TOTP, JWT HS*
• CRC CRC-32, CRC-32C, CRC-16 (MODBUS, CCITT-FALSE, XMODEM), CRC-8, CRC-64/XZ, Adler-32
• Password passphrases from the EFF wordlist (7776 words, ~12.9 bits each), random passwords and random keys (hex / Base64, like openssl rand), all from the browser's CSPRNG
• UUID generate v4, v7 and ULID; paste one to see its version, variant and embedded time; a name gives its UUID v5 (DNS and URL namespaces)
• Cipher AES-256-CBC with a passphrase, byte-compatible with openssl enc -pbkdf2 (and the legacy -md md5 format); decrypt reads both
• IP IPv4 and IPv6: canonical form, decimal, hex, binary, PTR name, address type (private, link-local, ULA, documentation…); for a prefix — network, netmask and wildcard, first / last host, broadcast, host count
• URL scheme, host (with the Unicode form of an IDN), port, path, decoded query parameters, fragment, credentials, origin, normalized form; a bare host is read as https
• Time Unix time (seconds or milliseconds), ISO 8601, RFC-1123 or "2019-02-27 09:36:55" in → all of them out, with the weekday, ISO week and day of the year; durations both ways: 90061 → 1d 1h 1m 1s, "1h 30m" / "01:30:00" / PT1H30M → seconds
• Num a number in any base in (decimal, 0x hex, 0b binary, 0o octal, Roman, floating point), the others out: decimal, hex, octal, binary, Roman, bit count, size in KiB / kB, IEEE-754 double and single
• Strings length in characters, bytes, words and lines; UTF-8 / UTF-16 (BE and LE) ↔ hex; code points; UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, slug
• JWT decode, claims with expiry as local time; verify HS* with the secret, RS* / PS* / ES* / EdDSA with a PEM or JWK public key; sign a JSON payload with HS256
• Encode Base64 / Base64url, Base32, Base58 (encode and decode, binary shown as hex), encodeURI, encodeURIComponent, HTML special characters, ROT13
• Cron schedule builder (every N minutes, hourly, daily, weekly with weekdays, monthly, yearly) ↔ crontab expression, plain-English description and the next 5 runs; lists, ranges, steps, names, @daily and friends; six-field expressions with seconds (Quartz, Spring)
• JSON pretty-print, minify and YAML (optionally with sorted keys), quote as a JSON string — a pasted string literal is unquoted on the spot; syntax errors with the position
• Diff compare two texts side by side, line by line, with the changed characters highlighted; ignore whitespace / case

Enter text, click a result to copy it. The last tab is remembered. Keyboard: Alt+1…9, Alt+0 jump to a tab, Alt+[ / Alt+] go to the previous / next one. The theme icon toggles between following the OS and the opposite look.

MIT license, source on GitHub. Uses crypto-js, js-sha3, blakejs and the EFF large wordlist (CC BY 4.0).