Free Developer Tools
Format JSON, test regular expressions, decode JWTs, generate hashes and UUIDs, convert CSV and Base64, and more. These utilities run entirely client-side, so API keys, tokens and payloads you paste in are never transmitted.
25 developer tools
JSON Formatter & Validator
Format, beautify, validate and minify JSON with clear error messages.
{ }JSON Minifier
Compress JSON by removing whitespace and line breaks.
→,JSON to CSV Converter
Convert a JSON array of objects into CSV for Excel or Google Sheets.
,→CSV to JSON Converter
Convert CSV or spreadsheet data into JSON.
B64Base64 Encode & Decode
Encode text to Base64 or decode Base64 back to text, with UTF-8 support.
%20URL Encoder & Decoder
Percent-encode or decode URLs and query string values.
&;HTML Entity Encoder & Decoder
Escape or unescape HTML special characters.
.*Regex Tester
Test regular expressions live with match highlighting and capture groups.
IDUUID Generator
Generate random v4 UUIDs in bulk.
#!Hash Generator (SHA-256, SHA-1, SHA-512)
Create SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text.
JWTJWT Decoder
Decode JSON Web Tokens to inspect header, payload and expiry.
tsUnix Timestamp Converter
Convert Unix epoch time to a readable date and back.
* *Cron Expression Explainer
Translate cron schedules into plain English.
</>XML Formatter
Pretty-print and validate XML.
SQLSQL Formatter
Beautify SQL queries with line breaks and indentation.
MDMarkdown to HTML Converter
Convert Markdown to clean HTML with a live preview.
CSSCSS Minifier
Minify CSS to cut file size and speed up your site.
HTMHTML Minifier
Shrink HTML by stripping comments and extra whitespace.
◐Color Converter (HEX, RGB, HSL)
Convert colours between HEX, RGB and HSL with a live swatch.
▤CSS Gradient Generator
Build linear and radial CSS gradients and copy the code.
▣CSS Box Shadow Generator
Design CSS box shadows visually and copy the code.
://URL Parser
Break a URL into protocol, host, path, query parameters and hash.
0xNumber Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
404HTTP Status Codes Reference
Look up what any HTTP status code means.
▭Screen Resolution Checker
See your screen size, viewport, pixel ratio and browser details.
Frequently asked questions
Can I safely paste tokens and API responses?
The tools run locally in your browser and send nothing over the network. Still avoid pasting live production secrets into any website as a general habit.
Do these tools work offline?
Once a page has loaded, most tools keep working without a connection.