Small, fast, private tools

Everything here runs locally in your browser — nothing you type is uploaded, and every tool keeps working offline once the page has loaded.

Security

Hash & ChecksumSHA digests of text or a whole file, HMAC signing, and a constant-time checksum comparison.Encrypt a MessageLock text behind a password with AES-256-GCM, then send the blob over any channel you like.JWT InspectorDecode a token, read its claims in local time, and actually verify the signature — HMAC, RSA or ECDSA.TOTP CodesTurn a 2FA secret into live six-digit codes, or mint a new secret and otpauth link for your own service.Secrets & KeysAPI keys, UUIDs, AES keys and real ECDSA/RSA key pairs in PEM — generated by the browser, never sent anywhere.

Developer

Cron ExplainerRead a cron expression in plain English and see exactly when it fires next, in your own time zone.Diff CheckerCompare two blocks of text line by line, with word-level highlighting inside the lines that changed.

Time

Timer & StopwatchCountdown timers with presets and a lap stopwatch — accurate even when the tab is in the background.Time Zone PlannerLine up a day across cities, see who is still awake, and copy a meeting time everyone can read.

Random

RandomizerNumbers, dice, coin flips, shuffles and team splits — all from the browser’s cryptographic RNG.