Powerful tools.
Simple & free.
Calculators, image tools, text utilities and developer helpers — all in one clean place. No signup, no clutter.
Popular tools
Tools people use most
Area Calculator
Calculate the area of circles, rectangles, squares, triangles and more.
YouTube Thumbnail Downloader
Download YouTube thumbnails in every available quality.
Image Resizer & Compressor
Resize and compress images right in your browser.
Loan Calculator
Calculate monthly payments and total interest.
BMI Calculator
Check your Body Mass Index and healthy weight range.
JSON Formatter & Validator
Format, validate and minify JSON — fully in your browser.
MathKit
Scientific calculator plus powers & roots, GCD/LCM, primes, quadratic solver and statistics.
Negative Marks Calculator
Calculate exam score with 1/4, 1/3, 1/2 or custom negative marking.
Why MasterKit
Everything you need, in one place
Simple, useful and accessible online tools that help you get things done faster.
Fast & easy
Get results instantly with simple tools designed for everyday tasks.
Privacy friendly
Your data stays in your browser whenever a tool can process it locally.
Works everywhere
Use every tool comfortably on desktop, tablet or mobile.
Many categories
Finance, health, math, images, text, YouTube and developer tools.
Simple to use
No setup. Pick a tool, enter your values and get your answer.
Always improving
New tools and improvements are added regularly.