Free Online Developer Tools — DevToys Web Pro

What DevToys Web Pro Is

DevToys Web Pro is a free, browser-based collection of developer tools covering every common task: format and validate JSON, encode and decode Base64, generate UUIDs, decode JWT tokens, test regular expressions, convert between data formats, hash strings, generate QR codes, compress images, and more — all without installing software or sending data to a server. Every tool runs entirely in your browser using JavaScript and WebAssembly, so your code, credentials, and sensitive data never leave your machine.

Tool Categories

Tools are organized into eight categories. Formatters: JSON formatter, SQL formatter, XML formatter, CSS formatter, HTML formatter, JavaScript formatter, YAML formatter, TOML formatter. Encoders & Decoders: Base64 encoder/decoder, URL encoder/decoder, JWT decoder, HTML entity encoder, hex/ASCII converter, Base58, gzip, quoted-printable. Generators: UUID/GUID generator, password generator, QR code generator, hash generator, HMAC generator, RSA key generator, bcrypt generator, lorem ipsum generator, TOTP/OTP generator. Converters: JSON to YAML, JSON to CSV, JSON to TOML, cron expression parser, chmod calculator, date converter, number base converter, curl-to-code, markdown to HTML. Testers: regex tester, JSON Schema validator, JSONPath tester, XML/XSD validator, URL parser, query string parser, IBAN checker, password strength checker. Text tools: markdown preview, text diff/comparer, text analyzer, string replacer, list compare. Image tools: image compressor, image converter, image resizer, image cropper. Network tools: IPv4 subnet calculator, IPv4 range expander, IPv6 parser.

Privacy — Your Data Stays in Your Browser

Unlike many online developer tools that send your input to remote servers for processing, DevToys processes everything locally. When you format JSON, decode a JWT, test a regex, or hash a string, the computation runs in your browser tab using the same JavaScript engine and Web Crypto API that power modern web applications. No data is transmitted, no inputs are logged, and the tools continue working offline after the page loads. This makes DevToys safe to use with JWT tokens, API keys, private keys, credentials, and any other sensitive developer data.

Browser Tool vs Local App

DevToys Web Pro works instantly in any browser with no installation, no login, and no configuration. It is also available as a Progressive Web App (PWA) for offline use, and as a browser extension for Chrome, Firefox, and Edge that puts all tools in your new-tab page. For teams, the web version requires no software deployment — share a URL and anyone on any OS can use the tools immediately. Compared to running scripts locally or configuring VS Code extensions, DevToys is faster to access for one-off formatting, decoding, or conversion tasks.