Developer Tools
Everyday utilities for working with code and data: formatters, encoders, and generators that run entirely client-side.
Popular Developer Tools
JSON Formatter
Format, validate, and beautify JSON with proper indentation.
Base64 Encoder / Decoder
Encode text to Base64, or decode Base64 back to plain text.
URL Encoder / Decoder
Encode text for safe use in a URL, or decode a URL-encoded string.
UUID Generator
Generate random, version-4 UUIDs for use in code or databases.
Hash Generator
Generate a SHA-1, SHA-256, or SHA-512 hash of any text.
HTML Encoder / Decoder
Encode text to HTML entities, or decode HTML entities back to plain text.
All Developer Tools
JSON Formatter
Format, validate, and beautify JSON with proper indentation.
Base64 Encoder / Decoder
Encode text to Base64, or decode Base64 back to plain text.
URL Encoder / Decoder
Encode text for safe use in a URL, or decode a URL-encoded string.
UUID Generator
Generate random, version-4 UUIDs for use in code or databases.
Hash Generator
Generate a SHA-1, SHA-256, or SHA-512 hash of any text.
HTML Encoder / Decoder
Encode text to HTML entities, or decode HTML entities back to plain text.
Color Converter
Convert between HEX and RGB color formats.
Regex Tester
Test a regular expression against sample text and see all matches.
PX to REM Converter
Convert pixel values to rem units for CSS, with a configurable root font size.
REM to PX Converter
Convert rem units to pixel values, with a configurable root font size.
CSS clamp() Calculator
Generate a fluid CSS clamp() value that scales between a minimum and maximum size across viewport widths.
REST API Client
Send GET, POST, PUT, PATCH and DELETE requests to any REST API and inspect the response, right in your browser.
Fake Data Generator
Generate rows of realistic synthetic test data (names, emails, dates, numbers…) as JSON, CSV, XML, Python, SQL or YAML.
JSON to YAML Converter
Convert JSON to YAML or YAML to JSON, in either direction.
Password Generator
Generate a strong, random password using your browser's secure random number generator.
JWT Decoder
Decode a JWT's header and payload locally, without sending the token anywhere.
SQL Formatter
Format and beautify a SQL query for MySQL, PostgreSQL, SQLite, MariaDB or SQL Server.
curl Command Generator
Build a curl command from a method, URL, headers and body.
Related Guides
Frequently Asked Questions
- Are the tools in Developer Tools free to use?
- Yes — every tool is free, with no sign-up and no usage limits.
- Does my data leave my browser?
- No — every tool in Developer Tools processes your input entirely on your device. Nothing is uploaded to a server.
- How do I find a specific tool?
- Use the search bar in the header, or browse the full list below — each tool links to a page with an explanation and a worked example.