Compress PDF Online — Free, Private, No Upload
Drop a PDF file here, or
Files stay on your device — nothing is uploaded.
70%
Lower quality means a smaller file. Around 70% keeps scans readable.
Large photos are scaled down to this longest side before re-encoding.
Make a heavy PDF small enough to email or upload. The tool finds the photos packed inside the file, re-encodes them at the quality you choose, and rewrites the document — all on a PDF engine that runs in your browser, so scans, reports, and portfolios never leave your machine.
How it works
- 1 Choose your PDF Drop the file onto the box or click to pick it. It's read locally and its page count and image count show up right away.
- 2 Set the quality Drag the quality slider and pick a maximum image size. Lower quality and smaller images mean a smaller file.
- 3 Compress and download Click Compress. The tool re-encodes the images and shows how much it saved, then hands you the lighter PDF to download.
Your data stays private
All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.
Frequently asked questions
- Is my PDF uploaded to a server?
- No. Reading the file, re-encoding its images, and writing the smaller PDF all happen in JavaScript inside your browser. Nothing is transmitted, so the tool keeps working even if you disconnect from the internet after the page loads.
- How does the compression actually work?
- Most of the weight in a big PDF is embedded photographs. The tool decodes each JPEG image, optionally scales it down to the size you set, and re-encodes it at your chosen quality. Text, fonts, and vector graphics are copied through untouched, so the pages stay sharp and the text stays selectable.
- Why didn't my file get smaller?
- If a PDF is mostly text, tables, or vector drawings, there are no photos to re-compress, so there's little to remove — the tool rewrites the file and reports that it was already well optimized. It never hands back a file larger than the one you gave it.
- Will compressing blur my scans?
- Lower the quality far enough and yes, you'll see JPEG softening — that's the trade for a smaller file. Start around 70% quality with a 1600-pixel cap; it usually cuts the size a lot while staying readable. Bump the quality back up if a scan looks rough.
- Are bookmarks and form fields kept?
- The pages, their text, and their images are all preserved. Document-wide extras like bookmarks, the outline, and interactive form fields are not carried into the rebuilt file. If you need those, compress a copy and keep the original.
- Can I compress a password-protected PDF?
- Not directly. Encrypted files are turned away with a clear message. Open the PDF in a reader, save an unprotected copy, then compress that.