How it works

1. You open a tool

Your browser downloads the web page and the JavaScript code for that tool from our static hosting — the same as visiting any website. Heavier engines (the PDF reader, Word writer, image encoders) are only downloaded when you open a tool that needs them.

2. You choose files

When you select or drop a file, the browser gives the page access to that file's bytes in memory. Nothing is sent over the network. We say “Choose files”, not “Upload”, because there is no upload.

3. Processing happens on your device

• PDF pages are read and rendered with PDF.js (Mozilla) and created or edited with pdf-lib.
• Word documents are written with the docx library and read with mammoth.
• Images are decoded and encoded with your browser's built-in canvas, which also verifies the real output format.
• ZIP files for batch downloads are created with fflate.

4. You download the result

Results are created as files in memory and saved with your browser's normal download feature. You see the real size, page count or dimensions before you download. Your original file is never modified.

Network requests that do happen

Loading pages, scripts, fonts and the PDF engine's worker and data files from our own domain. That's it: no analytics, ads, trackers or third-party scripts are loaded on tool pages. You can verify this in your browser's developer tools (Network tab).

Practical limits

Your device does the work, so very large files depend on its memory and speed. The tools apply conservative limits to stay reliable:

• Up to 104.8576 MB per file or batch.
• Up to 300 PDF pages per document.
• Up to 40 megapixels per image.

Phones and older computers may be slower. Closing or reloading the tab ends the session and releases files from memory. Releasing memory isn't guaranteed forensic erasure — it's ordinary browser memory management.

See Privacy for the full data policy and Supported formats for what each tool accepts.