Compress PDF
Shrink a PDF to fit email or upload limits.
How it works
Shrink a PDF so it fits an upload limit or email attachment. Pick how hard to compress, and you'll see the before and after size before downloading. Works best on scanned documents and image-heavy PDFs.
How it works: pages are re-rendered as images at a lower resolution and quality, then rebuilt into a new PDF. That's very effective for scanned documents (often several times smaller), but it rasterises text — so use it when file size matters more than selectable text.
🔒 Your file is processed entirely in this browser — it is never uploaded to a server. No signup, no watermark, no page limits.
🔒 Your document never leaves your device: unlike most online PDF tools, which upload your file to their servers, everything here runs locally in your browser. There is no upload, no account, no watermark and no page or file-count limit — so it's safe for contracts, invoices, medical records and anything else confidential.
About the Compress PDF
This free PDF compressor shrinks a PDF so it fits an email attachment or an upload limit. Choose how hard to compress and you'll see the before and after size — and the percentage saved — before you download anything.
Compression runs in your browser, so your document is never uploaded. No signup, no watermark, no size cap.
How to compress a PDF
- Choose your PDF.
- Pick a level: Light keeps the most quality, Strong gives the smallest file.
- Compare the before and after size, then download if you're happy.
How the compression works
Each page is re-rendered as an image at a lower resolution and quality, then rebuilt into a new PDF. That is extremely effective for scanned and image-heavy documents, which are usually what makes a PDF large. The trade-off is that text becomes part of the image, so it is no longer selectable or searchable — the tool warns you when your PDF contains real text.
Frequently asked questions
How do I reduce the size of a PDF?
Upload nothing — just choose your file here, pick a compression level, and compare the resulting size. Scanned and image-heavy PDFs typically shrink dramatically.
Will compressing lose quality?
Some, yes. Pages are re-rendered at a lower resolution, so there's a visible trade-off at the strongest setting. Start with the recommended level and go stronger only if you need to.
Why didn't my PDF get smaller?
Text-based PDFs are already compact, so rasterising them can produce a similar or even larger file. Compression pays off most on scans and photo-heavy documents — keep your original if the result isn't smaller.
Will the text still be selectable?
No. Because pages become images, text can no longer be selected or searched. Use this when file size matters more than editable text.
Is my file uploaded?
No. Compression happens entirely in your browser, so your document never leaves your device.