Free developer tools
Format. Decode. Convert. Instantly.
30+ browser-based developer utilities. No sign-up, and every tool
runs in your browser. Paste, transform, copy.
Popular tools
View all 30+ tools →JSON Formatter
Format & validate
Beautify, minify, and validate JSON with syntax highlighting and error detection.
Base64 Encoder & Decoder
Encode & decode
Encode text or files to Base64 and decode Base64 back to text or a downloadable file.
Regex Tester
Test & debug
Test JavaScript regular expressions with live match highlighting, capture groups, a replace preview, and a cheat sheet.
JWT Decoder
Decode & inspect
Decode JWTs, inspect the header and payload, check expiry, and verify signatures.
Color Converter
HEX, RGB, HSL
Convert any CSS color, including names, alpha, and oklch(), to HEX, RGB, HSL, and CMYK.
URL Encoder & Decoder
Encode & decode
Percent-encode and decode URLs and query values, including strict RFC 3986 and form encoding.
The free online developer toolkit — built for daily use
DevToolbox gives developers instant access to the utilities they search for every day. Whether you need a JSON formatter online, a Base64 encoder and decoder, a regex tester, JWT decoder, or a color format converter — it's all here, free, and runs entirely in your browser.
Frequently asked questions
Are all tools free?
Yes. All 30+ tools are free forever. No account, no paywall, no usage limits — ever.
Is my data safe when I use these tools?
Every tool processes your input in your browser, so what you type isn't sent to a server. The only exception is the Share link button, which uploads the tool's current output when you click it.
Can I share my tool output with a teammate?
Yes. The Share link button uploads the tool's current output and copies a link to it that anyone you send it to can open.
Do I need to install anything?
No. DevToolbox is entirely browser-based. Open the tool, paste your input, get your output — nothing to install.
What kinds of tools are available?
Formatters, encoders, decoders, converters, generators, validators, minifiers, and comparators — covering JSON, Base64, JWT, regex, color, URL, UUID, hash, diffs, and more.
Do you add new tools?
Yes. New tools are added regularly based on developer requests and search trends.