Free Compress PDF
Shrink PDF file size in your browser.
What is the Compress PDF?
A PDF that's too big to email or slow to upload is one of the most common file headaches — especially scanned documents, which can balloon to tens of megabytes.
This PDF compressor shrinks those files right in your browser, so you can get a scan or image-heavy PDF down to an emailable size without uploading it anywhere.
Last updated: Aug 14, 2026
What does this tool do?
You upload a PDF and pick a compression level, and the tool re-renders each page as an optimized image at that quality, then rebuilds the PDF from those pages.
It shows the before and after sizes and the percentage saved, and lets you download the smaller file — all locally, with nothing uploaded.
Key features
Real size reduction
Big savings on scanned and image PDFs.
Compression levels
Balance quality against file size.
Before/after sizes
See exactly how much you saved.
Private
Runs in your browser; nothing uploaded.
No sign-up
Free, with no account.
Example
Common use cases
- Anyone emailing PDFs — Get under attachment size limits.
- Students — Upload scans within a portal's cap.
- Job seekers — Shrink a scanned CV or certificate.
- Admin staff — Compress scanned paperwork.
- Small businesses — Send lighter invoices and forms.
- Legal & finance — Reduce heavy scanned documents.
- Anyone with a slow upload — Cut upload time.
- Archivers — Store scans more compactly.
Benefits
- It dramatically shrinks scanned and image-heavy PDFs.
- It keeps your document on your device.
- It shows the savings so you can pick the right level.
- It needs no software or sign-up.
Tips
- It works best on scanned or image-heavy PDFs — that's where the big savings are.
- Start with the balanced level, and only go higher if you need a smaller file.
- Remember the output is rasterized, so text won't be selectable afterward.
- For text-based PDFs, compression may not help — the file is already small.
- Keep the original if you'll need to edit or search the text later.
- Very large PDFs take longer, since every page is re-rendered.
- Combine with Split PDF first if you only need part of a big document.
- Check the after-size before downloading to confirm it met your target.
Common mistakes to avoid
Compressing a text PDF and expecting big savings
Fix: Text PDFs are already small; this helps scans and image-heavy files most.
Needing selectable text afterward
Fix: Compression rasterizes pages — keep the original if you need to search or edit text.
Choosing the highest level by default
Fix: Start balanced; only increase compression if the file must be smaller.
Discarding the original
Fix: Keep a copy in case you need the full-quality, text-based version later.
How it works
- 1
Upload a PDF
Ideally a scan or image-heavy file.
- 2
Pick a level
Balance quality against size.
- 3
Download
Get the compressed PDF.
Frequently asked questions
It re-renders each page as an optimized image at the compression level you choose, which greatly shrinks scanned and image-heavy PDFs.
No — because pages are rasterized, text becomes part of the image. It's ideal for scans; for text-based PDFs the size may not drop.
No. Compression runs entirely in your browser and the file never leaves your device.
It re-renders each page as an optimized image at your chosen level, which greatly shrinks scanned and image-heavy PDFs.
No. Because pages are rasterized, text becomes part of the image. It's ideal for scans; for text PDFs the size may not drop.
No. Compression runs entirely in your browser and the file never leaves your device.
It's probably a text-based PDF, which is already compact. This tool helps most with scans and image-heavy files.
Very large PDFs are supported but take longer, since each page is re-rendered; extremely long files are capped for performance.
Yes, completely free with no sign-up.
Conclusion
A PDF compressor turns an unemailable scan into a lightweight file in seconds, privately in your browser. Pair it with Split PDF and Merge PDF to trim and reassemble documents before compressing.