Free developer tools

Developer tools that work.
Without the friction.

Encode, decode, validate, and convert in the browser. Nothing you paste is sent to a server. No signup.

Free online tools for everyday engineering work: a UUID v4 and v7 generator, Unix timestamp to date converter, cron expression parser, JWT decoder, YAML validator, and JSON formatter.

Client-side only No signup No tracking

Popular tools

Identifiers UUID Generator Generate UUID v4, sortable UUID v7, or legacy v1. Bulk up to 100, copy all, no hyphens or URN. Time Unix Timestamp to Date Convert epoch time to a human-readable date and back. Seconds or milliseconds, any timezone. Schedules Cron Expression Parser Paste a cron expression, get plain English plus the next run times. Auth JWT Decoder Decode a JWT and inspect header, payload, and expiry without sending the token anywhere. Data YAML Validator Validate YAML syntax, see line-level errors, and convert YAML to JSON. Data JSON Formatter Beautify, minify, and validate JSON entirely in the browser.

All developer tools

UUID Generator Timestamp Converter Cron Parser JWT Decoder YAML Validator JSON Formatter JSON Validator Base64 Encoder Hash Generator Regex Tester SQL Formatter XML to JSON URL Encoder Case Converter View all →

Guides

What is a UUID?

Meaning, format, and when to use v4 vs v7.

Unix timestamp to date

Convert epoch time in JS, Python, SQL, and the shell.

Cron expression examples

Common schedules in plain English.