PDF Converter + Combine
Combine PDFs, turn images into a PDF, or turn a PDF's pages into images — all in your browser.
Engineering Calculators
Injection-mould design & FE-exam calculators — free, in your browser.
Image Converter
Convert any image to PNG, JPG or WEBP — drop in JPG, PNG, WEBP, GIF, BMP, SVG or AVIF. Batch-convert and download everything as a ZIP. Files never leave your device.
Edit & Sign PDFs
Open a PDF or start blank. Add text, draw, erase, drop in a signature — then save.
Weekly Planner
Type into any time slot. Click the circle to mark done. Saves automatically to your account.
Settings
Manage your password, how the app looks, its language, and your offline backup.
Appearance
Language
Change password
Offline backup
Welcome to Charitools
A free toolkit for everyday work — PDF tools, a planner, a focus timer, work-hours tracking, and mechanical engineering calculators. Pick a tool to begin.
Unit Converter
Convert between units by category — length, area, volume, mass, force, pressure, energy, power, torque, speed, temperature and more.
Focus Timer
A Pomodoro timer: focus, then break. It rings and notifies you when the session ends.
Work Hours
Keep a log of the days and hours you work, so you can remember them and export the list. It exports in the app's current language.
| Date | Day | Start | End | Break (min) | Hours | Notes | |
|---|---|---|---|---|---|---|---|
| Total | 0.00 | ||||||