Free Online Developer Tools

🔥 Popular Tools

🔑 JWT Decoder

Decode any JWT token. Header, payload, signature shown colour-coded. Expiry, issuer, subject displayed. 100% browser-side.

⚡ JSON Validator

Validate JSON instantly online. Get real-time syntax error detection with line & position context, key count, depth, and size stats. 100% free, runs in your browser

🔄 JSON ↔ YAML Converter

Convert JSON to YAML or YAML to JSON online instantly. Perfect for Kubernetes configs, Docker Compose, CI/CD pipelines, and Ansible playbooks. Free, bidirectional, no signup.

🎲 Mock JSON Generator

Generate realistic fake JSON data instantly. Choose from 8 templates: User, Product, Order, Post, Company, Transaction, Event, IoT Sensor. Up to 50 records, downloadable. Free, no signup

📁 Developer Tools

🔍 JSON Diff Checker

Compare two JSON objects and instantly see what changed, was added, or removed. Flat key-level diff with added/removed/changed highlighting. Perfect for API response debugging.

⚡ JSON Validator

Validate JSON instantly online. Get real-time syntax error detection with line & position context, key count, depth, and size stats. 100% free, runs in your browser

🗜️ JSON Minifier

Minify and compress JSON online in one click. Remove whitespace, reduce file size up to 40%, and see exact byte savings. Free, instant, browser-based — no data sent to servers

📐 JSON Schema Generator

Auto-generate JSON Schema (Draft-07) from any JSON sample. Detects types, formats (email, UUID, date), required fields, and nesting. Free online tool — no signup, instant results