Developer Tools
Free browser-based utilities built for developers — runs entirely client-side, no data leaves your machine, no sign-up required.
Format, validate, minify and compare JSON data instantly.
Decode and inspect JWT tokens or encode new ones, fully client-side.
Encode or decode Base64 strings and files including images.
Encode or decode URLs and individual URL components.
Test regular expressions with live match highlighting and capture groups.
Convert Unix timestamps to readable dates in any timezone.
Turn a cron expression into plain English and see the next run times.
Generate UUIDs (v1, v4, v7) or ULIDs in bulk.
Encode and decode HTML entities with a full reference table.
Build CSS gradients visually and copy the ready-to-use code.
Write Markdown and see the rendered HTML output side by side.
Compare two texts and highlight exactly what changed.
Generate complementary, triadic or analogous colour palettes.
Format and beautify SQL queries for MySQL, Postgres and SQLite.
Searchable reference for every HTTP status code with examples.
Minify your HTML, CSS or JavaScript and see the size savings.
About these developer tools
This collection covers the quick tasks developers reach for daily. Every tool here runs entirely in your browser — no server round-trips, no accounts, no rate limits. Paste a minified JSON blob and get clean, readable, indented output in one step. Decode a JWT token and inspect the header, payload, and expiry without sending it anywhere. Test a regex pattern against live sample data with match highlighting and named group extraction.
Whether you're debugging an API response, cleaning up a CI pipeline config, converting timestamps across timezones, or exploring an unfamiliar data structure — these tools are built to get out of your way and let you work.