API
EN
English 中文 Español Português Français
Not signed in Access your API key, usage and plan.
Log in Create free account Developer API
40 free tools

Developer Tools

Everyday developer utilities — format JSON, encode and decode Base64 and URLs, generate hashes and convert number bases — all client-side and instant.

JSON Formatter Beautify and validate JSON with clean indentation. JSON Minifier Strip whitespace to make JSON as small as possible. Base64 Encode Encode text to a Base64 string. Base64 Decode Decode a Base64 string back to text. URL Encode Percent-encode text so it is safe in a URL. URL Decode Decode percent-encoded text back to readable characters. HTML Encode Escape characters into safe HTML entities. HTML Decode Turn HTML entities back into normal characters. Hash Generator Generate SHA-1, SHA-256 and SHA-512 hashes of any text. Number Base Converter Convert numbers between binary, octal, decimal and hex. Text to Binary Convert any text into its binary (base-2) representation. Binary to Text Convert binary (base-2) code back into readable text. Unix Timestamp Converter Convert a Unix timestamp to a readable date in UTC and local time — or get the current epoch. JWT Decoder Decode a JSON Web Token to read its header and payload in plain JSON. JSON to CSV Convert a JSON array of objects into clean CSV for Excel or Sheets. CSV to JSON Convert CSV with a header row into a tidy JSON array of objects. URL Parser Break any URL into its protocol, host, path, hash and query parameters. What's My IP See your public IP address and what your browser reveals. Regex Tester Test a regular expression against your text and see every match highlighted live. Cron Expression Parser Turn a cron schedule into plain English and see when it runs next. Markdown Previewer Write Markdown and see it rendered live, right in your browser. JSON Viewer Paste JSON and explore it as a collapsible, colour-coded tree. JSON Validator Check whether JSON is valid — and if not, get the exact error, line and column. JSON Editor Edit JSON with one-click format, minify and sort-keys, and live validation. JSON to XML Converter Turn JSON into well-formed XML, with arrays as repeated elements. XML to JSON Converter Turn XML into clean JSON, keeping attributes and grouping repeated tags. TSV to JSON Converter Turn tab-separated data (with a header row) into a JSON array of objects. JSON to TSV Converter Turn a JSON array of objects into tab-separated values for a spreadsheet. JSON to Text Converter Flatten JSON into plain, readable indented lines of key and value. HTML Beautifier Turn messy or minified HTML into clean, properly indented markup. HTML Minifier Shrink HTML by removing comments and whitespace, safely. CSS Beautifier Turn minified or messy CSS into clean, readable, indented rules. CSS Minifier Shrink CSS by removing comments and whitespace, safely. JavaScript Beautifier Turn minified or messy JavaScript into clean, indented code. JavaScript Minifier Shrink JavaScript by stripping comments and whitespace — safely, never breaking it. Credit Card Validator Check whether a card number passes the Luhn checksum and see its card type. VTT to SRT Converter Convert WebVTT subtitles to numbered SRT, fixing the timestamp format. SRT to VTT Converter Convert SRT subtitles to WebVTT, adding the header and fixing timestamps. JSON to TypeScript Paste JSON and get clean, nested TypeScript interfaces with types inferred automatically. XML Formatter Paste messy XML and get clean, indented output — or minify it to a single line, with validity checked as you go.

About Developer Tools

This category gathers thirty-eight of the small utilities that developers open a dozen times a week and never want to install, now including a full JSON toolkit — viewer, validator and editor — and HTML, CSS and JavaScript beautifiers and minifiers. It covers formatting and inspection with the JSON formatter and JSON minifier, encoding with Base64 encode and URL encode, and debugging helpers like the JWT decoder and regex tester. If you are reading an API response, untangling a redirect chain, decoding something a log spat out, or converting data between formats, one of these will finish the job faster than writing a throwaway script.

Pick by the shape of the problem. Broken or unreadable data usually means the JSON formatter first, since it pretty-prints valid JSON and points at the spot where invalid JSON goes wrong. Data that needs to change format is a job for JSON to CSV or CSV to JSON. Anything that looks like gibberish is probably encoded: try Base64 decode, URL decode or HTML decode depending on whether you see padding characters, percent signs or entities. Timestamps that arrive as a long integer go into the Unix timestamp converter, and a cron line nobody can read goes into the cron expression parser, which spells the schedule out in English. The URL parser breaks a long link into its parts, the number base converter handles hex and binary, and the markdown previewer shows how a README will render before you push it.

What these tools have in common matters as much as what they do. They are free and need no sign-up, and they run entirely client-side: the payload you paste, the token you are inspecting and the config you are debugging stay in your browser and are never uploaded. That is the point for a developer tool — you should be able to drop a staging API response into a textarea without wondering where it went. The one thing to remember is that the JWT decoder decodes and displays a token; it does not verify its signature, so never treat a decoded token as proof of anything. For hashing, see hash and security.

Frequently asked questions

Is my data sent to a server when I use these tools?

No. These tools run entirely in your browser, so the JSON, tokens and text you paste never leave your device. The one exception is What's My IP, which by its nature has to ask a server what address your request came from.

Does the JWT decoder verify the token signature?

No. It decodes the header and payload so you can read the claims, but it does not check the signature against a secret or public key. A decoded token proves nothing about authenticity, so never use it as a security check.

Why does the JSON formatter reject my JSON?

Almost always because it is not strictly valid JSON. Common causes are trailing commas, single quotes instead of double quotes, unquoted keys, comments, or a JavaScript object literal copied from source code rather than real JSON output.

Can I use these tools offline?

Mostly yes. Once a client-side tool's page has loaded, it keeps working without a connection because the logic runs in your browser. Tools that need to look something up over the network, like What's My IP, will not.

Other tool categories

Text Color Hash Generators SEO Social Testing Timers CSS Legal Encoding Image Webmaster YouTube