Developer Tools
100+ free online tools for developers, testers, and teams. No signup required. All processing happens in your browser - your data never leaves your device.
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Markdown
Live markdown editor with preview
Password
Generate secure random passwords
Regex
Test and debug regular expressions
Diff
Compare two texts and see differences
Words
Count words, characters, sentences and get reading time
SQL
Format and beautify SQL queries online
JSON/YAML
Convert between JSON and YAML formats
Converter
Convert between JSON, YAML, XML, CSV, and generate code
Browse by Category
Format & Convert
Code formatters and data converters
JSON
Format, validate, and minify JSON
Markdown
Live markdown editor with preview
SQL
Format and beautify SQL queries online
JSON/YAML
Convert between JSON and YAML formats
Converter
Convert between JSON, YAML, XML, CSV, and generate code
HTML
Format and beautify HTML code online
CSS
Format and beautify CSS code online
JS
Format and beautify JavaScript code online
Encode & Security
Encoding, hashing, and security tools
Generate
Generators for UUIDs, passwords, and more
UUID
Generate and validate UUIDs (v4)
GUID
Generate GUIDs (Globally Unique Identifiers) for .NET and Windows
Password
Generate secure random passwords
Cron
Generate and explain cron expressions
Lorem
Generate placeholder text
QR Code
Generate QR codes for URLs, WiFi, contacts
Project Names
Generate creative names for projects and repos
Mock Data
Generate realistic mock data for testing
Text & Data
Text manipulation and data processing
Regex
Test and debug regular expressions
Diff
Compare two texts and see differences
Words
Count words, characters, sentences and get reading time
Case
Convert text between different cases
Slug
Convert text to SEO-friendly URL slugs
JSONPath
Test JSONPath expressions against JSON data
String Utils
Various text manipulation and extraction tools
Time & Math
Time converters and calculators
Timestamp
Convert between Unix timestamps and dates
Afford This
See the true cost of purchases in hours of your life
Subscriptions
Calculate how much you spend on subscriptions monthly
Timezones
Convert times between timezones and plan meetings
Pomodoro
Focus timer with work/break intervals
Meeting Cost
Calculate the true cost of meetings
Base Convert
Convert numbers between decimal, binary, octal, and hexadecimal
Units
Convert between different units of measurement
Design
CSS generators and design tools
Colors
Convert colors between HEX, RGB, HSL formats
PX/REM
Convert between px, rem, em, and pt units
PPI/DPI
Calculate PPI, DPI buckets for any screen
Aspect Ratio
Calculate dimensions for any aspect ratio
Breakpoints
Responsive breakpoints for Tailwind, Bootstrap, MUI
Spacing
Generate consistent spacing scales for design systems
Gradient
Create beautiful CSS gradients with live preview
Shadow
Generate CSS box shadows with multiple layers
Dev Tools
Web development and AI tools
Tokens
Count tokens for AI models (GPT, Claude)
API Test
Test REST APIs with GET, POST, PUT, DELETE requests
Meta Tags
Generate SEO meta tags and Open Graph tags
OG Preview
Preview how your links appear on social media
Schema
Generate JSON-LD structured data
Robots
Create robots.txt files for search engines
Sitemap
Create XML sitemaps for SEO
cURL
Convert cURL commands to code
Team Tools
Collaboration and planning tools for agile teams
Sprint Names
Generate creative sprint names for agile teams
Quiz
Generate fun quiz questions for team meetings
Trivia
Compete in trivia with your team
Spinner
Random decision maker with spinning wheel
T-Shirt
Convert T-shirt sizes to story points for agile planning
PERT
Three-point estimation with confidence intervals
Story Points
Estimate stories with complexity factors and sprint capacity
Poker
Estimate stories with your team in real-time
Fun & Games
Team activities, quizzes, and fun tools for breaks
About Our Developer Tools
TheDevToolbox provides a comprehensive collection of free online tools designed specifically for software developers, QA engineers, DevOps professionals, and technical teams. Every tool runs entirely in your browser, ensuring your data stays private and secure.
Our collection includes essential utilities like JSON formatters and validators, Base64 encoders and decoders, UUID generators, and regex testers. For teams practicing agile methodologies, we offer planning poker, sprint retrospective tools, and estimation calculators. Designers will find CSS generators for gradients, shadows, and color palettes useful for rapid prototyping.
All tools are completely free to use with no registration required. Whether you need to quickly format some JSON, generate test data, or calculate Unix timestamps, TheDevToolbox has you covered with fast, reliable, and easy-to-use utilities.