Supercharge Your Dev Workflow
Your all-in-one toolkit for everything dev work throws at you — converters, generators, calculators, code playgrounds, and a growing reference library, all in your browser.
No downloads. No sign-ups. No setup. Just open a tab and get to work.
Recently Visited Tools
Why Choose CoolDev.Tools?
All-in-One Toolkit
From quick conversions to full code playgrounds to a growing reference library — converters, generators, calculators, and docs, all in one place.
Browser-Based
Use all tools directly in your browser without installing any software or dependencies.
Secure & Private
Your data stays in your browser or isolated containers — private and secure.
Quick Reference, Always Within Reach
Stop digging through MDN tabs. Look up what you need, fast.
HTTP Status Codes
All 63 official codes plus the unofficial ones devs actually hit, with causes, fixes, and examples.
View ReferenceMore coming: HTTP Headers, HTTP Methods, Cron Syntax
Featured Tools
Try our most popular developer tools
Code & Run
Run Python, Rust, Go, C/C++, and PHP playgrounds, decode JWTs, lint JSON, and test regex — all in your browser.
ExploreConvert & Format
CSV ↔ JSON, cURL converter, Base64, unit converters, URL encode/decode, and more.
ExploreFiles & Generators
Favicon generator, HTML/Base64-to-PDF, QR codes, ASCII art, sitemap generator.
ExplorePopular Languages
Choose from a wide variety of programming languages
Run Rust Online – Compile and Execute Rust Code Instantly
Run C Online – Compile and Execute C Programs Instantly
Run Python Online – Execute Python Code Instantly in Your Browser
Run C++ Online – Compile and Execute C++ Programs Instantly
PHP Code Runner – Run PHP Code Online (Multiple Versions Supported)
Run Go Online – Compile and Execute Go Programs Instantly
Popular Calculators
Try our most popular calculators
CAGR Calculator
Compute the annualized growth rate from initial and final values over years.
Try NowEMI Calculator
Calculate monthly EMI for home, car, or personal loans based on principal, interest rate, and tenure.
Try NowPercentage to CGPA
Convert between percentage and CGPA using standard formulas — handy for transcripts, applications, and eligibility checks.
Try NowYour Dev Workflow, Minus the Friction
Conversions, calculators, code playgrounds, generators, and quick reference — all in one place, all free, no installs.