Free web apps and software, built by MafLabs
MafLabs is a software lab that builds fast, useful web apps and makes them free to use. Every app opens in your browser, so there is nothing to install. We started with utilities for developers, and we now build apps for everyday life too.
Our apps
One lab, many apps. Pick one and start using it.
JSON Formatter
Format, validate and beautify JSON, explore it as a tree, and share it with a link that expires after one hour.
JSON Compare
Compare two JSON files and see the differences, ignoring whitespace and property order.
JSON to CSV
Preview your data, pick the fields you need and download a clean CSV file. Nothing is uploaded.
cURL Builder
Build cURL requests with headers, authentication and a body for Bash, CMD or PowerShell.
API Tester
Send requests, check status codes and read formatted responses. Sign in only to save collections.
Webhook Tester
Get a unique URL, catch incoming webhooks in real time and inspect every request.
NicheCalc
Dozens of free calculators for health, money, cooking, cars, pets and more.
Couple Games
Multiplayer relationship games, newlywed-style quizzes and quick mini-games to play with your partner.
How we build
Browser-first.
Every MafLabs app is a web app. Open it and use it, with no download.
Fast and focused.
Each app does one job well.
Privacy-minded.
The JSON Formatter and JSON to CSV apps work in your browser. The formatter sends data to our server only if you choose to share a link.
Free to use.
The apps listed here cost nothing.
Always improving.
New apps and features are added over time.
Frequently asked questions
MafLabs is a software lab that builds free web apps, from developer utilities to everyday calculators and games. Built by an independent team focused on delivering high-quality tools.
Yes. The apps listed on this page are free to use.
No installation is needed, because every app runs in your browser. Most apps need no account. The API Tester asks you to sign in only if you want to save collections and sync them across sessions.
The JSON Formatter and JSON to CSV apps process your data in your browser. The JSON Formatter sends data to our server only if you click Share, and shared links expire after one hour. Check each app's page for its own details.
Email contact@maflabs.online. Contact us.
About MafLabs
MafLabs is an independent software lab that builds simple, useful web apps. We began with developer utilities and expanded into apps for everyday life.