Small tools that just work.
Free, no-signup utilities for people who write code. Everything runs in your browser — nothing you paste is ever sent to a server.
JSON Formatter & Validator
Paste messy JSON, get it formatted, minified, or validated instantly.
Open tool →Cron Expression Generator
Build and decode cron schedules in plain English.
Coming soonRegex Tester
Test patterns against sample text with live match highlighting.
Coming soonJSON to CSV Converter
Flatten JSON arrays into a downloadable CSV file.
Coming soonBase64 Encode / Decode
Convert text and files to and from Base64 instantly.
Coming soonTimestamp Converter
Unix timestamp to human-readable date, and back.
Coming soonWhy Fieldkit
Most "free tool" sites bury a simple conversion under trackers, forced signups, or ten seconds of interstitial ads. Fieldkit does one thing: give you a working instrument, on one page, that runs entirely in your browser. No account, no upload, no rate limit.
How it works
Every tool here is static — the JavaScript that formats your JSON or parses your cron expression runs locally on your machine. Nothing you type or paste is transmitted anywhere, which also means the tools work offline once the page has loaded.