Developer Tools
50 free browser-based tools for developer workflows
Free Developer Tools Online
Use these developer tools for short, repeatable engineering tasks: format API responses, decode tokens, test regular expressions, convert data formats, inspect URLs, and generate values for local tests. Most tools run directly in the browser and are designed for quick copy-and-paste workflows.
Built for developers who need fast utilities without opening an IDE plugin, account dashboard, or command-line helper.
Category scope
50
tools indexed in this hub
Recommended starting points
These pages match the highest-intent tasks in this category and link onward to nearby tools and guides.
JSON Format/Validate
Format, validate, and beautify JSON with syntax highlighting
JWT Decoder
Decode and inspect JSON Web Tokens
Regex Tester
Test and debug regular expressions with live matching
Base64 Encode/Decode
Encode text to Base64 or decode Base64 strings
SQL Formatter
Format and beautify SQL queries
cURL to Fetch Converter
Convert cURL commands to JavaScript fetch code
Common tasks
Start from the job you need to finish, then open the closest utility.
All developer tools
JSON Format/Validate
Format, validate, and beautify JSON with syntax highlighting
JWT Decoder
Decode and inspect JSON Web Tokens
Regex Tester
Test and debug regular expressions with live matching
Base64 Encode/Decode
Encode text to Base64 or decode Base64 strings
SQL Formatter
Format and beautify SQL queries
cURL to Fetch Converter
Convert cURL commands to JavaScript fetch code
Backslash Escape/Unescape
Escape or unescape backslash sequences in text
Basic Auth Generator
Generate HTTP Basic Authorization headers
Unix Time Converter
Convert timestamps to human-readable dates and vice versa
CSV to JSON
Convert CSV data to JSON array format
URL Encode/Decode
Encode or decode URL components and query strings
URL Parser
Break URLs into protocol, host, path, query, and hash parts
2FA Code Generator
Generate TOTP verification codes from a 2FA secret
JSON to YAML
Convert JSON data to YAML format
YAML to JSON
Convert YAML data to JSON format
HTML Entity Encode/Decode
Encode or decode HTML entities and special characters
JSON to CSV
Convert JSON arrays to CSV format
JSON Diff
Compare two JSON documents and highlight differences
JSON Minify
Minify JSON by removing whitespace and formatting
JSON Path Tester
Test JSONPath expressions against JSON data
Cron Expression Parser
Parse and explain cron schedule expressions
UUID Generator
Generate random UUIDs (v4) instantly
ULID Generator
Generate sortable unique identifiers
Hash Generator
Generate SHA-256, SHA-512, and other hash digests
HMAC Generator
Create keyed message authentication codes
HTTP Status Code Reference
Browse and search all HTTP status codes
MIME Type Lookup
Find MIME types by extension or extension by MIME type
User-Agent Parser
Parse browser, OS, device, and rendering engine from a user agent
Keycode Info
Inspect JavaScript keyboard event values
Random Port Generator
Generate random available-looking development ports
IPv4 Subnet Calculator
Calculate network, broadcast, host range, and masks
IPv4 Address Converter
Convert IPv4 addresses between dotted, decimal, hex, and binary
JSON to TypeScript Interface
Generate TypeScript interfaces from JSON data
Markdown to HTML Converter
Convert Markdown syntax to clean HTML
HTML to Markdown Converter
Convert HTML code to Markdown syntax
XML Formatter & Validator
Format, beautify, and validate XML documents
CSS Minifier
Minify CSS by removing whitespace and comments
JavaScript Minifier
Minify JavaScript by removing whitespace and comments
HTML Minifier
Minify HTML by removing whitespace and comments
.gitignore Generator
Generate .gitignore files for any project type
Unix Permission Calculator
Calculate Unix file permissions in numeric and symbolic notation
TOML to JSON Converter
Convert TOML configuration to JSON format
JSON to TOML Converter
Convert JSON configuration to TOML
TOML to YAML Converter
Convert TOML configuration to YAML
YAML to TOML Converter
Convert YAML configuration to TOML
JSON to XML Converter
Convert JSON data to XML format
XML to JSON Converter
Convert XML documents to JSON
HTML Table to CSV
Extract HTML table data into CSV format
Base32 Encode/Decode
Encode text to Base32 or decode Base32 strings
JSON Schema Generator
Generate JSON Schema from sample JSON data
Related guides
Guide
How to use Backslash Escape/Unescape
Escape or unescape backslash sequences in text
Guide
How to use Base64 Encode/Decode
Encode text to Base64 or decode Base64 strings
Guide
How to use JSON Format/Validate
Format, validate, and beautify JSON with syntax highlighting
Guide
How to use Unix Time Converter
Convert timestamps to human-readable dates and vice versa
Guide
How to use CSV to JSON
Convert CSV data to JSON array format
Guide
How to use Regex Tester
Test and debug regular expressions with live matching
Guide
How to use URL Encode/Decode
Encode or decode URL components and query strings
Guide
How to use JWT Decoder
Decode and inspect JSON Web Tokens
FAQ
Are these developer tools free?
Yes. The developer utilities are free to use in the browser and do not require an account.
Do I need to install anything?
No. Each tool is available as a standalone web page, so quick formatting, decoding, and conversion tasks can run from a browser tab.