Free Developer Tools for Code, Data and Everyday Web Work
Format code, test patterns, encode values and convert technical data with free developer tools that run directly in your browser. No signup or installation required.
Choose the task you need to complete
Format and validate code
JSON Formatter & Validator
Format, minify and validate JSON instantly in your browser.
Check with JSON Formatter & Validator DeveloperYAML Formatter & Validator
Validate and normalize common YAML mappings, lists and scalar values locally.
Check with YAML Formatter & Validator DeveloperSQL Formatter
Format common SQL statements with readable clauses and indentation.
Format with SQL Formatter DeveloperJSON Schema Validator
Validate JSON data against common JSON Schema type and property rules.
Check with JSON Schema Validator DeveloperHTML Minifier
Remove comments and unnecessary whitespace from HTML.
Use HTML Minifier DeveloperCSS Minifier
Reduce CSS whitespace and comments for production.
Use CSS Minifier DeveloperJavaScript Minifier
Apply conservative comment and whitespace reduction to JavaScript.
Use JavaScript Minifier DeveloperRegular Expression Tester
Test JavaScript regular expressions and inspect matches.
Use Regular Expression Tester DeveloperMarkdown Preview
Preview safe basic Markdown and copy generated HTML.
Preview with Markdown PreviewEncode, decode and inspect
Base64 Encoder & Decoder
Encode text as Base64 or decode Base64 back into readable UTF-8 text.
Convert with Base64 Encoder & Decoder DeveloperURL Encoder & Decoder
Encode or decode URL components safely in your browser.
Convert with URL Encoder & Decoder DeveloperHTML Entity Encoder & Decoder
Encode reserved HTML characters or decode entities locally.
Convert with HTML Entity Encoder & Decoder DeveloperJWT Decoder
Decode JSON Web Token headers and payloads without sending the token away.
Convert with JWT Decoder DeveloperURL Parser & Query Builder
Inspect URL components and edit query parameters.
Use URL Parser & Query Builder DeveloperSVG Data URI Converter
Encode SVG markup for use inside CSS data URLs.
Convert with SVG Data URI ConverterGenerate identifiers and values
UUID Generator
Generate one or many random RFC 4122 version 4 UUIDs.
Create with UUID Generator DeveloperHash Generator
Generate SHA-256, SHA-384 or SHA-512 hashes from text locally.
Create with Hash Generator DeveloperRandom String & ULID Generator
Generate secure random strings or sortable ULID identifiers.
Create with Random String & ULID Generator DeveloperFile Checksum Generator
Calculate SHA-256, SHA-384 or SHA-512 for a local file.
Create with File Checksum Generator DeveloperCron Expression Generator
Build common five-field cron schedules with a readable explanation.
Create with Cron Expression Generator DeveloperUnix Timestamp Converter
Convert Unix timestamps to readable local and UTC dates.
Convert with Unix Timestamp ConverterInspect systems and networks
HTTP Header Parser
Parse pasted HTTP request or response headers into a readable table.
Use HTTP Header Parser DeveloperUser-Agent Parser
Identify common browsers, operating systems, devices and bots from a user-agent string.
Use User-Agent Parser DeveloperChmod Calculator
Build Unix file permissions from readable owner, group and public controls.
Use Chmod Calculator DeveloperIPv4 CIDR Subnet Calculator
Calculate network, broadcast, host range and address count for an IPv4 CIDR.
Use IPv4 CIDR Subnet CalculatorConvert technical values
Binary Text Converter
Convert UTF-8 text to binary bytes and back.
Convert with Binary Text Converter DeveloperNumber Base Converter
Convert integers between binary, octal, decimal and hexadecimal.
Convert with Number Base Converter DeveloperDate Difference Calculator
Calculate elapsed calendar time between two dates.
Use Date Difference CalculatorFree Developer Tools for Code, Data and Everyday Web Work
Format code, test patterns, encode values and convert technical data with free developer tools that run directly in your browser. Each utility concentrates on one clear task, making it easier to get a useful result and continue working.
Start with the group that matches your goal, then follow the related-tool suggestions for the logical next step. Most processing happens in your browser, without an account or unnecessary uploads.
Developer tools questions
Do these developer tools upload my code?
Most tools process the supplied value directly in your browser. Check the individual tool page for any exception.
Do I need to install a package?
No. These utilities work in a modern browser without npm packages, extensions or an account.