DeveloperTools

Free Online Developer Tools

323+ free tools for developers. Format, validate, convert, and generate code. All processing happens in your browser — fast, private, and no signup required.

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Popular Tools (16)

JSON Formatter
Format and beautify JSON data with proper indentation
JSON Validator
Validate JSON data and detect errors
Base64 Encode
Encode text to Base64
Base64 Decode
Decode Base64 to text
URL Encoder
Encode text for safe URL usage
JWT Decoder
Decode and inspect JWT tokens
UUID Generator
Generate random UUID v4
SQL Formatter
Format and beautify SQL queries
Timestamp Converter
Convert between timestamps and dates
Regex Tester
Test regular expressions against text
JSON to YAML
Convert JSON to YAML format
CSV to JSON
Convert CSV data to JSON format
Hash Generator
Generate SHA-1/256/384/512 hashes and HMAC
Random Password Generator
Generate passwords with Web Crypto API
Markdown Editor
Write Markdown with live HTML preview
Color Picker
Pick colors visually with preset swatches

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All Calculators (323)

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Encoders & Formats
JSON Formatter
Format and beautify JSON data with proper indentation
JSON Validator
Validate JSON data and detect errors
JSON Viewer
View JSON data in a tree structure
JSON Minifier
Minify JSON by removing whitespace
JSON to CSV
Convert JSON arrays to CSV format
CSV to JSON
Convert CSV data to JSON format
JSON to YAML
Convert JSON to YAML format
YAML to JSON
Convert YAML to JSON format
JSON to TypeScript
Generate TypeScript interfaces from JSON
JSON Diff
Compare two JSON objects and find differences
JSON to XML
Convert JSON data to XML format
JSONPath Tester
Test JSONPath expressions against JSON data
JSON Schema Generator
Generate JSON Schema from JSON data
JSON Escape/Unescape
Escape and unescape JSON strings
JSON Flattener
Flatten and unflatten JSON objects
JSON Path Extractor
Extract data using JSONPath expressions
JSON Merge Tool
Merge multiple JSON objects
JSON to SQL
Convert JSON data to SQL statements
JSON to HTML Table
Convert JSON arrays to HTML tables
JSON Diff Online
Compare two JSON objects online
Base64 Encode
Encode text to Base64
Base64 Decode
Decode Base64 to text
Image to Base64
Convert images to Base64 data URIs
Base64 to Image
Convert Base64 data to images
Base64 File Converter
Convert files to and from Base64
URL-safe Base64
URL-safe Base64 encoding and decoding
URL Encoder
Encode text for safe URL usage
URL Decoder
Decode URL-encoded text
URL Parser
Parse and analyze URL components
URL Validator
Validate URL format
JWT Decoder
Decode and inspect JWT tokens
JWT Encoder
Create JWT tokens
JWT Validator
Validate JWT token structure
XML Formatter
Format and beautify XML data
XML Validator
Validate XML syntax and detect errors
XML to JSON
Convert XML data to JSON format
XML to CSV
Convert XML data to CSV format
XML to YAML
Convert XML data to YAML format
XML Escape/Unescape
Escape and unescape XML characters
XML to Markdown
Convert XML to Markdown format
YAML Formatter
Format and beautify YAML data
YAML Validator
Validate YAML syntax and detect errors
YAML to CSV
Convert YAML data to CSV format
YAML to TOML
Convert YAML to TOML format
YAML to XML
Convert YAML to XML format
YAML to SQL
Convert YAML data to SQL statements
YAML Diff
Compare two YAML documents
CSV Viewer
View CSV data as a formatted table
CSV Formatter
Format and align CSV columns
CSV to SQL
Convert CSV to SQL INSERT statements
CSV to HTML Table
Convert CSV data to HTML tables
CSV to Markdown Table
Convert CSV to Markdown tables
CSV Data Cleaner
Clean and fix messy CSV data
HTML Entity Encoder
Encode and decode HTML entities
ROT13 Encoder
Apply ROT13 cipher to text
Morse Code Translator
Convert text to Morse code and back
Hex to Text Converter
Convert between hexadecimal and text
Punycode Converter
Convert internationalized domain names
ASCII85 Encoder
Encode and decode ASCII85/Base85
ROT47 Encoder
Apply ROT47 cipher to text
HTML Entity Decoder
Decode HTML entities to text
Text & Content
Lorem Ipsum Generator
Generate placeholder text for designs and mockups
Text Statistics
Count words, characters, sentences, and reading time
Word Counter
Count words, characters, and sentences
Remove Duplicate Lines
Remove duplicate lines from text
Extract Emails
Extract email addresses from text
Extract URLs
Extract URLs from text content
Add Prefix & Suffix
Add prefix and suffix to each line
Remove Whitespace
Remove extra whitespace from text
Text to Columns
Split text into columns by delimiter
Join Lines
Join lines with custom separator
Remove Line Breaks
Remove line breaks from text
Extract Numbers
Extract numbers from text content
Sort Words
Sort words alphabetically
Reverse Word Order
Reverse the order of words in text
Text to ASCII
Convert text to ASCII character codes
Acronym Generator
Generate acronyms from text
Upside Down Text
Flip text upside down
Strikethrough Generator
Apply strikethrough to text
Small Caps Text
Convert text to small caps
Text to Hex
Convert text to hexadecimal
Word Shuffler
Shuffle words randomly
Zigzag Text
Create zigzag text pattern
Lorem Ipsum Generator
Generate placeholder text
Emoji Picker
Browse and copy emojis
Text Diff
Compare two texts and find differences
Text Case Converter
Convert text between camelCase, PascalCase, snake_case and more
Slug Generator
Generate URL-friendly slugs from text
String Reverser
Reverse text, words, or characters
Text Replacer
Find and replace text with regex support
Text Repeater
Repeat text with custom separators and counts
List Sorter & Deduplicator
Sort, deduplicate, and clean up lists
Word Frequency Counter
Count word and character frequency in text
Text Diff Checker
Compare two texts and highlight differences
Text Column Extractor
Extract specific columns from delimited text
Line Number Adder
Add line numbers to text in various formats
Text to Speech
Convert text to speech using browser TTS
String Length Calculator
Calculate string length in various encodings
Text Truncator
Truncate text with customizable ellipsis
Text to Handwriting
Convert text to handwriting style
Unicode Search
Search Unicode characters
Text Encoder
Encode text with different charsets
Markdown Editor
Write Markdown with live HTML preview
Markdown to HTML
Convert Markdown to HTML
HTML to Markdown
Convert HTML to Markdown format
Markdown Table Generator
Create Markdown tables visually
Markdown to HTML Table
Convert Markdown tables to HTML
HTML Formatter
Format and beautify HTML code with proper indentation
HTML Minifier
Minify HTML by removing whitespace and comments
HTML Preview
Preview HTML code in a sandboxed iframe
HTML Entity Encoder/Decoder
Encode and decode HTML entities
HTML Comment Stripper
Remove HTML comments from code
Developer
SQL Formatter
Format and beautify SQL queries
SQL Minifier
Minify SQL by removing whitespace
SQL Validator
Validate SQL syntax
SQL to TypeScript
Convert SQL schema to TypeScript interfaces
SQL INSERT Generator
Generate INSERT statements from data
Regex Tester
Test regular expressions against text
Regex Generator
Generate regex patterns from descriptions
Regex Validator
Validate regex syntax
UUID Generator
Generate random UUID v4
UUID Validator
Validate UUID format
MD5 Hash Generator
Calculate MD5 hash of text
SHA-256 Hash Generator
Calculate SHA-256 hash using Web Crypto API
SHA-512 Hash Generator
Calculate SHA-512 hash using Web Crypto API
Hash Generator
Generate SHA-1/256/384/512 hashes and HMAC
SHA-1 Hash Generator
Calculate SHA-1 hash using Web Crypto API
SHA-384 Hash Generator
Calculate SHA-384 hash using Web Crypto API
Bcrypt Hash Generator
Generate bcrypt hashes from text
Hash Type Identifier
Identify hash types by length and format
RIPEMD Hash Generator
Calculate RIPEMD-160 hash online
CRC32 Generator
Calculate CRC32 checksum of text
Code Diff
Compare two texts and highlight differences line by line
JSONPath Tester
Test JSONPath expressions against JSON data
Markdown Table Generator
Create Markdown tables visually
API Request Builder
Build and test API requests with cURL export
cURL to Code Converter
Convert cURL commands to JavaScript, Python, PHP, Go, Ruby, Java
HTTP Status Codes Reference
Browse and search HTTP status codes
JWT Debugger
Decode and inspect JWT tokens
CORS Header Generator
Generate CORS headers for Nginx/Apache/Express
Dockerfile Generator
Generate Dockerfile configurations for your projects
.gitignore Generator
Generate .gitignore files for your projects
Cron Expression Parser
Parse and explain cron expressions with next runs
Chmod Calculator
Calculate Unix file permissions numerically and symbolically
Docker Compose Generator
Generate docker-compose.yml files visually
.htaccess Generator
Generate Apache .htaccess files
JSON Schema Generator
Generate JSON Schema from JSON data
Fake Data Generator
Generate fake data for testing
README.md Generator
Generate README files for projects
Git Commit Message Generator
Generate conventional commit messages
Changelog Generator
Generate changelogs from commit history
License Picker
Choose the right open source license
JSON Escape/Unescape
Escape and unescape JSON strings
XML Escape/Unescape
Escape and unescape XML characters
CSV Data Cleaner
Clean and fix messy CSV data
MIME Type Lookup
Look up MIME types by file extension or vice versa
Unicode Character Lookup
Find Unicode characters, code points, and properties
Web & SEO
CSS Formatter
Format and beautify CSS code
CSS Minifier
Minify CSS by removing whitespace and comments
CSS Gradient Generator
Generate CSS gradients visually
CSS Unit Converter
Convert between px, rem, em, vw, vh units
CSS Box Shadow Generator
Generate box-shadow CSS visually
Border Radius Previewer
Preview border-radius visually
CSS Button Generator
Generate CSS button styles
CSS Animation Generator
Generate CSS keyframe animations
Font Pairing Tool
Find matching font combinations
Color Mixer
Mix colors together visually
CSS Filter Generator
Generate CSS filter effects
Tailwind Color Palette
Browse Tailwind CSS color palette
Spacing Calculator
Calculate spacing values
CSS Grid Generator
Generate CSS Grid layouts visually
CSS Selector Tester
Test CSS selectors against HTML
CSS Color Keywords
Reference CSS color keywords
JavaScript Formatter
Format and beautify JavaScript code
JavaScript Minifier
Minify JavaScript code
JavaScript Obfuscator
Obfuscate JS by renaming variables
Regex Tester
Test regex patterns with real-time matching
Meta Tag Generator
Generate SEO meta tags with Open Graph and Twitter Cards
Robots.txt Generator
Generate robots.txt files for your website
XML Sitemap Generator
Generate XML sitemaps for SEO
Open Graph Generator
Generate Open Graph meta tags for social sharing
URL Encoder/Decoder
Encode or decode URL strings
Schema.org Generator
Generate Schema.org JSON-LD markup
Keyword Density Checker
Check keyword density in text
Social Media Preview
Preview social media sharing cards
Canonical Tag Generator
Generate canonical URL tags
Hreflang Generator
Generate hreflang tags for SEO
Favicon Generator
Generate favicons for websites
Structured Data Tester
Test structured data markup
SEO Slug Checker
Check URL slugs for SEO
Robots.txt Validator
Validate robots.txt files
Sitemap Validator
Validate XML sitemaps
UTM URL Builder
Build URLs with UTM parameters
Color Blindness Simulator
Preview colors for color vision deficiencies
Alt Text Generator
Generate descriptive alt text for images
Contrast Ratio Checker
Check WCAG contrast ratios between colors
Color Blindness Test
Test color vision ability
Nginx Config Generator
Generate Nginx server configurations
Environment File Generator
Generate .env files with presets
package.json Generator
Generate package.json for Node.js projects
tsconfig.json Generator
Generate TypeScript configuration files
Math & Calculators
Percentage Calculator
Calculate percentages, increases, and decreases
Random Number Generator
Generate random numbers within a range
Tip Calculator
Calculate tips and split bills
Aspect Ratio Calculator
Calculate dimensions from aspect ratios
Statistics Calculator
Calculate mean, median, mode, std dev
GCD & LCM Calculator
Calculate greatest common divisor and LCM
Prime Number Checker
Check primality and find prime factorization
Scientific Notation Converter
Convert to/from scientific notation
Sequence Calculator
Fibonacci, Lucas, and custom sequences
Binary Calculator
Perform binary arithmetic
Number to Words
Convert numbers to words
Hex Calculator
Hexadecimal calculator
Standard Deviation
Calculate standard deviation
Z-Score Calculator
Calculate z-scores
Percentile Calculator
Calculate percentiles
Mean Median Mode
Calculate mean, median, and mode
Variance Calculator
Calculate variance
Combination Calculator
Calculate combinations and permutations
Fraction Calculator
Perform fraction arithmetic
Big Number Calculator
Calculate with large numbers
Matrix Calculator
Perform matrix operations
Logarithm Calculator
Calculate logarithms
Exponential Calculator
Calculate exponential functions
Modulo Calculator
Calculate modulo remainder
Pythagorean Calculator
Calculate triangle sides
Quadratic Solver
Solve quadratic equations
Percentage Change
Calculate percentage change
Ratio Calculator
Calculate ratios and proportions
Currency Converter
Convert between currencies
Loan Calculator
Calculate loan payments
Compound Interest
Calculate compound interest
ROI Calculator
Calculate return on investment
Salary Converter
Convert between salary periods
Tax Calculator
Calculate simple tax
Discount Calculator
Calculate discounts
Profit Margin
Calculate profit margin
Markup Calculator
Calculate markup percentage
Unit Price Comparator
Compare unit prices
Savings Calculator
Calculate savings growth
BMI Calculator
Calculate body mass index
Calorie Calculator
Calculate daily calorie needs
Macro Calculator
Calculate macronutrient ratios
Body Fat Calculator
Estimate body fat percentage
Heart Rate Zone
Calculate heart rate zones
Running Pace
Calculate running pace
Pregnancy Calculator
Calculate due date
Water Intake
Calculate daily water intake
Sleep Calculator
Calculate sleep cycles
Date Calculator
Calculate date differences and add/subtract days
Timezone Converter
Convert times between different timezones
Age Calculator
Calculate exact age with zodiac and birthday countdown
Timestamp to Date
Convert Unix timestamps to dates
World Clock Converter
Convert times between 19 time zones
Timestamp Difference
Calculate time between timestamps
Pomodoro Timer
Pomodoro technique timer
Countdown Timer
Online countdown timer
Stopwatch
Online stopwatch with lap times
Date Format Converter
Convert between date formats
Timezone Offset
Calculate timezone offsets
Timezone Meeting Planner
Plan meetings across timezones
Business Days Calculator
Calculate business days between dates
Leap Year Checker
Check if a year is a leap year
Day of Week Calculator
Find day of week for a date
Week Number Calculator
Find week number of a date