How PDF Compression Works Without Sending Your File Out
Key points
- Compression runs inside the browser
- The file is not stored on any external server
- On shared computers, delete saved files after use
With services that "upload your PDF to compress it", the document passes through a server. This site doesn't need that.
How it works
- When you open the page, the program needed for compression is loaded into the browser.
- The chosen PDF is read only in your device's memory and each page becomes an image.
- The images are assembled back into a PDF and saved to your device.
During this, the contents of the PDF are never sent out.
Suited for
Documents you don't want to leave your hands, such as transcripts, résumés and contracts.
Keep in mind
- The first load needs an internet connection
- Older browsers may not work
- On a shared computer, delete saved files after use
How to verify
On a computer, keep the browser developer tools "Network" tab open while compressing; you will see no requests carrying your file.
Use "Compress PDF" (free)Tools that go well with this
- Extract or Delete PDF Pages: Keep only the pages you need, or remove the pages you don't.
- Merge PDFs: Combine several PDF files into one, in the order you choose.
- Split PDF: Split a PDF into several files: one page each, every N pages, or by ranges.
More guides for this tool
- How to Compress a PDF to Fit a Size Limit
- What to Do When a PDF Is Too Big to Attach to an Email
- Why Text Can't Be Selected in a Compressed PDF
- Choosing Quality When Compressing: Small, Normal or High
- Why Scanned PDFs Are Heavy and How to Lighten Them
- Typical Upload Limits on Application Forms and How to Fit Within Them