Free online developer tools
Pasting an API response, a JWT, or a production config into a random website is a common way secrets leak. These utilities do the same everyday jobs — minify, beautify, format, encode, decode, hash, and generate — with code that runs in your browser tab, so the text you paste is not sent to a server.
Use them for quick checks while you work: minify a script before inlining it, format a SQL query for a code review, decode a token to inspect its claims, generate UUIDs for test data, or compare two versions of a file. Always validate transformed output in the environment where it will run.
27 developer tools tools
JavaScript MinifierCompress JS with Terser — mangle and squeeze in your browser.JSON FormatterPretty-print and validate JSON with clear error positions.SQL FormatterReformat messy SQL into clean, readable, uppercase-keyword style.JWT DecoderDecode a JWT's header and payload and check expiry.UUID GeneratorGenerate random and time-ordered UUIDs in bulk.Base64 EncodeEncode text to Base64 with full UTF-8 support.CSS BeautifierReformat CSS with clean indentation using Prettier.CSS MinifierStrip comments and whitespace to shrink your CSS.JavaScript BeautifierReformat minified or messy JS with Prettier.HTML BeautifierReindent messy HTML into clean, readable markup with Prettier.HTML MinifierCollapse whitespace and strip comments to shrink HTML.URL EncodePercent-encode text for safe use in URLs and query strings.HTML EscapeEscape special characters into safe HTML entities.SHA-256 GeneratorHash text or files with MD5, SHA-1, SHA-256, SHA-384, or SHA-512.Diff CheckerCompare two texts and highlight what changed.Word CounterLive word, character, sentence and reading-time stats.Case ConverterConvert text to camelCase, snake_case, Title Case and more.Slug GeneratorTurn titles into clean, SEO-friendly URL slugs.Timestamp ConverterConvert Unix time to ISO, local and human dates live.Base ConverterConvert between binary, octal, decimal, hex and any base.HEX to RGB ConverterConvert colors between HEX, RGB, HSL and OKLCH.QR Code GeneratorCreate QR codes for links and text — PNG or SVG.QR Code ReaderDecode a QR code from any image, privately.Barcode GeneratorCreate CODE128, EAN, UPC and more as SVG or PNG.Regex TesterTest regular expressions with live match highlighting.Cron Expression ParserExplain cron schedules and see the next run times.Lorem Ipsum GeneratorGenerate placeholder text by paragraphs, sentences or words.
Developer tools questions
The text is processed by JavaScript running in your browser and is not sent to a Convertur server. As with any tool, avoid pasting live production secrets unless you need to, and rotate anything that may have been exposed.
Minification removes whitespace and comments and shortens local names without changing behaviour. Test the minified output anyway, especially code that relies on function names or unusual syntax.
For a one-off check it is faster than installing a package or writing a script, and it works on any machine with a browser. For repeatable builds, put the same step in your toolchain instead.