ABOUT
About Tushuo Lab, simple things done simply.
Tushuo Lab (tushuoit.com/xx) is an online toolbox built on three ideas: lightweight, practical, playful. Open and use — no sign-up, no file uploads, fully usable on a phone.
The problem we solve
Typical tool sites demand registration, push your files to a server, or leave you guessing how a feature works. We reverse that order: anything that can run locally never goes online (compressing a photo should not mean sending it to someone else’s server), anything one-step never becomes a wizard, and anything explainable is explained on the page.
What is inside
- Images and PDF: compression, format conversion, cropping, mosaicking, merge and split, watermarking, signatures, OCR.
- Developer tools: JSON to type definitions, regex testing, hashing, Base64, timestamps, JWT, SQL formatting.
- Text and Chinese: text cleanup, simplified/traditional conversion, pinyin, word counting, typing speed.
- Everyday calculators: mortgage, income tax, compound interest, currency, unit conversion, BMI/BMR, due date, age, countdown.
- Learning: arithmetic drills, fractions, times tables, long multiplication, olympiad word problems (speed, work, mixture, chicken-rabbit, magic square, matchsticks) and solid geometry.
- Fun: minesweeper, sudoku, 24 game, daily number guessing, lottery wheel, stroke-order animation.
How we build
Front-end first: most tools are plain HTML, CSS and JavaScript. Where heavy lifting is unavoidable (video transcoding, OCR, PDF editing) we run WebAssembly locally so no server CPU is consumed. Assets are served from CDNs and pre-compressed where it helps first paint.
Content quality
Every tool documents how to use it plus the formula or principle behind it, and maths and teaching pages include visual animations that show the process instead of only the answer. Wherever we cannot guarantee a conclusion ourselves, the page says "for reference" instead of making a vague promise. Results are for reference — for health, financial or legal decisions please consult a professional.
Why no sign-up
A tool does not need an identity: everything runs in your browser and you leave when you are done. Adding accounts just to sync across devices usually turns a simple tool into one more password to remember, so for now we keep that complexity on our side.
Release cadence
The site keeps evolving: new tools, calibrated formulas, performance and accessibility work. Every release is listed in the changelog. If a figure or formula on a page looks outdated, tell us and we will verify and fix it.
Disclaimer
Calculations and content here are for reference only and do not constitute financial, medical or legal advice. For anything important, follow official guidance and consult a professional. Full details are in our Terms of Service.
Contact us
Feature requests, corrections, partnerships and advertising: email us through the contact page; we usually reply within a few business days.
Last updated：2026-09-24
FAQ
Is everything really free?
Yes. All tools are free with no usage limits and no registration. Running costs are covered by future advertising, which is why we care about keeping pages lightweight and fast.
Is there a mobile app?
No app is required. The site is responsive and works in mobile browsers, and installing the page to your home screen gives you an app-like entry point.