Everything You Need to Build, Learn & Calculate
Free developer tools, calculators, converters, an online code editor, and structured programming-language learning — all in one place, running entirely in your browser.
Everything, organized
Jump straight to the section you need — every tool, calculator, and lesson lives in one focused place.
Popular free tools
A few of the most-used tools — formatters, generators, and converters people reach for daily.
JSON Formatter
Pretty-print and indent minified or messy JSON.
JSON Validator
Check whether a JSON document is syntactically valid.
Word Counter
Count words, characters, sentences, and paragraphs.
UUID Generator
Generate random version 4 UUIDs.
Simple tools. Zero friction.
A growing collection of useful tools and lessons designed to get things done quickly, without unnecessary complexity.
Useful tools
Explore practical tools built to solve everyday development and business tasks faster.
Fast & simple
No setup and no accounts. Open a tool, add what you need, and get your result immediately.
Free to use
Every tool, calculator, and lesson is free — no subscriptions or hidden limits.
More every week
New tools, calculators, and learning content are added as the collection keeps expanding.
Ready to get started?
Pick a tool, run a calculation, or start learning a new language — everything here is free and ready whenever you are.