CodingTool

All Developer Tools

Browse our complete collection of 67 free online developer tools. All tools run locally in your browser for maximum privacy and speed.

JSON & Data Tools

10 tools
JSON Formatter
Format and beautify JSON data
YAML ⇄ JSON Converter
Convert between YAML and JSON
CSV ⇄ JSON Converter
Convert between CSV and JSON
XML ⇄ JSON Converter
Convert between XML and JSON formats
JSON Schema Validator
Validate JSON against schemas
JSON to TypeScript
Generate TypeScript interfaces
CSV Editor
Edit CSV files like a spreadsheet
YAML Viewer
View, parse, and validate YAML with tree view
JSON Diff Checker
Spot every change between two JSON objects instantly
CSV Diff Checker
Compare two CSV files with key-based diff and field-level change detection

Text & Encoding

7 tools
Base64 Encoder/Decoder
Encode and decode Base64 strings online
URL Encoder/Decoder
Encode and decode URLs safely
HTML Escape / Unescape
Encode and decode HTML entities online
String Case Converter
Convert text case formats
UUID/GUID Generator
Generate unique identifiers instantly
Lorem Ipsum Generator
Generate placeholder text for your designs instantly
Image ↔ Base64 Converter
Convert images to Base64 and decode Base64 back to images

Time & Date

6 tools
Unix Timestamp Converter
Convert timestamps to dates
Timezone Converter
Convert between timezones
ISO8601 Formatter
Format and parse ISO8601 dates
Age Calculator
Calculate age from birth date
Cron Expression Generator
Build, validate, and visualize cron schedules with timezone-aware simulation
Work Hours Calculator
Calculate work hours, WFO/WFH count, leave, business trips, client visits, and overtime using your company rules.

Code Utilities

10 tools
JavaScript Beautifier & Minifier
Format or minify JavaScript
CSS Beautifier & Minifier
Format, optimize, and minify CSS code
HTML Beautifier & Minifier
Format, optimize, and minify HTML code
Code Diff Checker
Compare code/text side-by-side
Markdown Editor & Previewer
Live markdown editor with preview
XML to Java Class Converter
Convert XML to annotated Java classes with JAXB & Lombok support
Schema Markup Validator
Validate JSON-LD schema markup and rich result readiness
HTML to Markdown Converter
Convert HTML and webpages into clean Markdown
Screenshot to Text & Code
Extract text and code from screenshots with local OCR
Source Map Stack Trace Resolver
Decode minified stack traces with source maps

Security Tools

9 tools
MD5 Generator
Generate MD5 hash from text or files
SHA256 Hash Generator
Generate SHA256 hashes
SHA512 Hash Generator
Generate SHA512 hashes
JWT Decoder
Decode JWT tokens
Password Generator
Generate secure passwords
JWT Generator
Generate JWT tokens with HS256
ENV Diff Comparator
Compare, audit & merge .env files with secret detection
ZIP with Password
Compress & encrypt files locally — no upload, no server.
AI Prompt PII & Secret Leak Scanner
Detect and redact sensitive data before sharing AI prompts

Developer Extras

22 tools
Regex Tester
Test regular expressions interactively
HTTP Header Parser
Parse HTTP headers
Fake Data Generator
Generate mock data
Commit Message Generator
Generate conventional commits
Currency Formatter
Format currency values
Array Sorter & Shuffler
Sort and shuffle arrays and objects
Word Counter
Count words, characters, sentences and paragraphs instantly
Swagger / OpenAPI Viewer
Visualize and explore OpenAPI 3.x and Swagger 2.0 specs instantly
QR Code Generator
Generate QR codes instantly from URLs, text, or JSON — no backend needed
Code Screenshot Generator
Create beautiful, shareable images of your code
Mini Postman (API Tester)
Test REST APIs directly in your browser — no install needed
Gitignore Generator
Generate production-ready .gitignore files for any tech stack
Image to WebP Converter
Convert images to WebP format instantly in your browser
GitHub Profile README Builder
Build a modular GitHub profile README with live preview
Broken Link Checker & Cleaner
Find, remove, and replace dead URLs from text, files, and webpages
Internet Speed Test
Check download speed, latency, jitter, and upload availability from your browser
Open Graph Previewer
Preview social cards and debug Open Graph, Twitter Card, and HTML metadata
Screenshot Full Webpage
Capture public webpages as full-page or viewport images
Mixpanel Toolkit
Local Mixpanel event sandbox
AI Coding Prompt Generator
Build clear, validated coding prompts for your favorite AI assistant.
Browser P2P File Transfer
Send files directly between two browsers using WebRTC. No upload, no account, no server storage.
Task Handoff Compiler
Turn messy requirements into an execution-ready engineering handoff with readiness checks, scope guards, and validation plans.

Math & Calculation

3 tools
Unit Converter
Developer-focused unit converter for data sizes, rates, time, and more
Decimal Precision Calculator
Precise decimal calculations
Number to Words Converter
Convert numbers to words in English and Indonesian with currency and check writing support

Why Use Our Developer Tools?

🔒 Privacy-First

All tools run entirely in your browser. Your data never leaves your device, ensuring complete privacy and security.

⚡ Lightning Fast

Client-side processing means instant results with no server delays or network latency. Tools work offline too.

🆓 100% Free

No registration, no subscriptions, no hidden fees. All tools are completely free to use without any limitations.

🌍 Multi-Language

Available in 10 languages including English, Chinese, Japanese, Russian, and more. Choose your preferred language anytime.

Popular Tool Categories

  • JSON & Data Tools: Format, validate, and convert JSON, YAML, CSV, and XML data
  • Text & Encoding: Encode/decode Base64, URL encoding, HTML escaping, and text transformations
  • Code Utilities: Beautify JavaScript, CSS, HTML, and compare code differences
  • Security Tools: Generate secure passwords, create JWT tokens, and calculate hash values
  • Developer Extras: Test regex patterns, parse HTTP headers, and generate fake data
  • Time & Date: Convert timestamps, format ISO 8601 dates, and convert between timezones
  • Math & Calculation: Unit conversions, age calculations, and precise decimal arithmetic

How to Use Our Tools

  1. Select any tool from the categories above
  2. Paste or type your input data
  3. Get instant results - no processing delay
  4. Copy, download, or share your results
  5. All data stays on your device for privacy