● 100% client-side · no sign-up · no tracking of your input

Developer tools that respect your data.

Format JSON, validate YAML, decode JWTs, generate UUIDs and build cron schedules. Fast, free and private — everything runs in your browser, so configs, tokens and secrets never touch a server.

{ }

JSON Formatter & Validator

Pretty-print, minify, validate and sort JSON with exact error positions.

 y:

YAML Validator & Converter

Validate YAML (multi-document too) and convert between YAML and JSON.

 jwt

JWT Decoder & Verifier

Decode JWT header and payload, check expiry, verify HMAC signatures.

 id

UUID Generator

Generate UUID v4 and time-ordered v7 in bulk, and inspect any UUID.

 */5

Cron Expression Generator

Build and explain cron schedules in plain English, see the next runs.

Why another set of developer tools?

Most online formatters send whatever you paste to their servers. That is a problem when the “whatever” is a production config, a Kubernetes secret or a live access token. Every tool here is plain JavaScript running in your browser tab: you can load the page, go offline, and it keeps working.

Built for everyday DevOps and backend work

  • JSON — pretty-print API responses, minify payloads, find the exact line of a syntax error.
  • YAML — check Kubernetes manifests, Helm values, docker-compose and CI files before you push.
  • JWT — inspect claims and expiry while debugging auth, verify HMAC signatures locally.
  • UUID — generate v4 or time-ordered v7 IDs for database keys and test fixtures.
  • Cron — write and sanity-check crontab and Kubernetes CronJob schedules with the next run times.