# How mypdf processes files in your browser

> How mypdf.space processes PDFs in your browser: File API, Web Workers, Network-tab proof. Link to How it works.

Canonical: https://mypdf.space/guides/how-mypdf-processes-files-in-your-browser
Last updated: 2026-10-22

## Direct answer

Tools read your file in the tab and write a download locally. Confirm with the Network tab and the How it works page.

## Introduction

“No upload” should be checkable. mypdf is built so you can prove it in a minute.

## Steps

1. Open How it works for the short architecture story.
2. Open DevTools → Network.
3. Run Compress or Privacy checker on a sample file.
4. Confirm no multipart PDF upload to mypdf.space.

## What still uses the network

Page HTML, analytics beacons, and first-time OCR language packs may download. Your PDF bytes are not the payload.

## Limits

- Offline needs install / cache.
- Very large files are limited by device memory.

## FAQ

### Where is the full explanation?

See /how-it-works and /security-methodology.

### What analytics run?

Listed on the Privacy page (GA, Clarity, DataFast).

### Can I use tools offline?

Yes after install as an app for many tools.

## Related

- [Compress PDF](https://mypdf.space/tools/compress)
- [Privacy scanner](https://mypdf.space/tools/privacy-scanner)
- [Confidential Send](https://mypdf.space/tools/workflow)
- [All guides](https://mypdf.space/guides)