Question 1

How do I compress a PDF for free?

Accepted Answer

Drop a PDF on the box above, pick a compression level (Low / Medium / High), and click Compress. We strip metadata and repack object streams to shrink the file, then offer the smaller PDF for download — all without uploading.

Question 2

Are my files uploaded to a server?

Accepted Answer

No. PrivatePDFConvert compresses PDFs entirely in your browser using JavaScript and pdf-lib. Your file never leaves your device.

Question 3

How much smaller will my PDF get?

Accepted Answer

Typical savings are 5–25% for text-heavy PDFs. Image-heavy or already-optimised PDFs see less benefit because the bulk of their bytes are already-compressed images. We're working on optional image re-encoding for Pro to push savings higher.

Question 4

What's the difference between Low, Medium, and High?

Accepted Answer

Low keeps the file structure mostly intact and just re-saves cleanly. Medium strips metadata and switches to PDF object streams, which packs internal objects more tightly. High applies the same techniques as Medium with the most aggressive lossless settings.

Question 5

Will compression hurt the quality of my PDF?

Accepted Answer

Our current compression is lossless: text stays sharp, vectors stay crisp, and images are not re-encoded. Visual quality is identical to the original.

Question 6

What's the maximum file size?

Accepted Answer

The free tier supports PDFs up to 25 MB. Pro raises that to 100 MB.

Question 7

Does this work on mobile?

Accepted Answer

Yes — choose a PDF on iOS or Android, pick a level, and the compression runs on your device. Larger PDFs are faster on a desktop browser.

Compress a PDF, free

Drop a PDF to compress

How it works

Frequently asked questions

Other tools

PDF to Word

PDF to Text

PDF Merge

PDF Split