Formatters, encoders & everyday dev utilities

Format JSON, encode and decode Base64 or URLs, test regex, minify code, and convert between data formats — free, fast, and built to run entirely in your browser.

31 tools in total
JSON FormatterFormat, beautify, and validate JSON data online for free.Base64 EncoderEncode text and files to Base64 online for free.Base64 DecoderDecode Base64 strings back to text online for free.URL Encoder DecoderEncode and decode URLs and query parameters online for free.UUID GeneratorGenerate random UUID v4 identifiers online for free.JWT DecoderDecode and inspect JWT tokens online for free.Regex TesterTest and debug regular expressions online for free with real-time matching.HTML MinifierMinify HTML code online for free.CSS MinifierMinify CSS stylesheets online for free.JavaScript MinifierMinify JavaScript code online for free.HTML BeautifierBeautify minified or messy HTML code online for free.CSS BeautifierBeautify minified or messy CSS code online for free.JavaScript BeautifierBeautify minified or messy JavaScript code online for free.JSON to CSV ConverterConvert between JSON and CSV formats online for free.JSON to TypeScriptGenerate TypeScript interfaces from a sample JSON object.JSON DiffCompare two JSON objects and see what changed.XML to JSON ConverterConvert between XML and JSON formats online for free.XML FormatterFormat and indent XML for readability, or minify it.YAML to JSON ConverterConvert between YAML and JSON formats online for free.CSV ViewerView, search, and analyze CSV files online for free.Base64 Image Encoder DecoderEncode images to Base64 or decode Base64 to images online for free.Text Diff CheckerCompare two texts online with line-by-line diff highlighting.Unix Timestamp ConverterConvert Unix timestamps to human-readable dates and back.Number Base ConverterConvert numbers between binary, octal, decimal, and hexadecimal.HTML Entity Encoder DecoderEncode and decode HTML entities online for free.SQL FormatterFormat a SQL query onto clean, readable lines.Cron Expression GeneratorBuild a cron expression with a live plain-English description.Online Markdown EditorWrite Markdown with a live preview and HTML export.HTML to Markdown ConverterConvert HTML markup into clean Markdown syntax.Gitignore GeneratorBuild a .gitignore file from language and tool templates.Hex to RGB ConverterConvert colors between HEX, RGB, and HSL.
About this category

What are developer tools?

Developer tools are the small utilities that come up dozens of times during a normal coding session — formatting a blob of minified JSON to actually read it, decoding a JWT to check its claims, encoding a string to Base64 for an API header, or testing a regular expression before dropping it into production code. None of these need a full IDE or a CLI install; they need a page that opens in a second, does the one transformation correctly, and doesn't get in the way of the rest of the work.

Every tool in this collection runs the transformation directly in the browser. The JSON formatter, XML/YAML/CSV converters, and minifiers parse and rewrite the input the moment it changes, using the same parsing logic a build tool would use — just without the build step. The UUID generator and hash-adjacent tools compute results using the browser's own crypto and random APIs. Nothing is sent to a server to be processed, so there's no upload step and no delay between pasting code in and seeing the result.

Who uses these tools, and for what

Backend developers reach for the JSON formatter and JWT decoder while debugging an API response, and the timestamp converter and number base converter when reading logs or working across binary, hex, and decimal. Frontend developers use the CSS and JavaScript minifiers to check output size, and the HTML entity encoder when handling text that needs to render safely. Anyone integrating with an API leans on the Base64 encoder/decoder and URL encoder/decoder for headers, tokens, and query strings, while the regex tester and diff checker help catch mistakes before they ship — comparing two versions of a file or validating a pattern against real sample input before it goes into code.

Why they're free, fast, and private by default

Code, API responses, and tokens pasted into a formatter or decoder are often sensitive — an auth header, a snippet from a private repo, a JWT carrying real user data. Every tool here processes that input locally in the browser tab only; nothing is transmitted to a server, logged, or retained after the tab closes. That also removes any file-size anxiety or network latency from the equation, so results appear the instant an input changes, whether it's five lines of JSON or five thousand.

That's the whole premise of this category: free, instant, and private enough to paste in real data without a second thought. No signup wall between a problem and its answer, and new developer tools are added here as they're built.

Explore the other tools

Pick a tool. Work now.
No signup, no upload, no waiting — just open a tool and get to work.