Compress PDF file size — free, no watermark
Reduce the size of a PDF right in your browser with Light, Medium, or Heavy presets. No upload, no watermark, completely private.
- ✓ No watermark
- ✓ No sign-up
- ✓ No file size limit
- ✓ Works offline
How to compress pdf
- 1Add your PDF using the box below (or drag it in).
- 2Pick a compression level — Light keeps the most quality, Heavy makes the smallest file.
- 3Click ‘Compress PDF’ and your smaller file downloads automatically.
Large PDFs are a hassle to email or upload — many services cap attachments at 10–25MB. Compressing a PDF trims it down to a shareable size while keeping it readable.
Unlike server-based compressors, pdfia never transmits your document. That matters for scanned IDs, contracts, and financial statements, where uploading a file to a third-party server is exactly what you want to avoid.
Frequently asked questions
＋ － How does compression work without uploading my file?
pdfia re-renders each page in your browser and re-encodes images at a lower quality, then rebuilds the PDF locally. Nothing is sent to a server.
＋ － How much smaller will my PDF get?
It depends on the file. Image-heavy and scanned PDFs shrink the most — often 50–80% on the Heavy preset. Text-only PDFs compress less.
＋ － Does compressing reduce quality?
Compression is a trade-off: Light preserves near-original quality, while Heavy prioritises the smallest size. For maximum compression, pages are flattened to images, so pick the level that fits your needs.
＋ － Is there a file size limit?
No hard limit — compression is bounded only by your device's memory, not by our servers (there are none).