Compress PDF
100% Private — No Upload RequiredShrink a PDF to email-friendly size by re-encoding each page as a compressed image. Best for scanned documents, image-heavy PDFs, and reports.
Drop a PDF here
One file · max 10 MB
How PDF compression works here
Each page of your PDF is rendered as an image at a chosen DPI, re-encoded as a compressed JPEG, and assembled into a fresh PDF. This is the same technique used by most online PDF compressors. Trade-off: text becomes part of an image, so it's no longer searchable or selectable. For text-heavy PDFs that need to stay searchable, consider splitting instead and only compressing the heavy pages.
How to use this tool
- Upload your PDF using the box above.
- Pick a compression level — Medium is a good default for most files.
- Click Compress PDF and download the smaller file.
How PDF compression works
PDFs containing scanned images are large because each page is essentially a high-resolution JPEG inside a PDF wrapper. This tool reduces file size by re-compressing those embedded images at lower quality and resolution. PDFs with mostly text and vector graphics are already small; compression of those typically saves only 10-30% because there's less image data to compress.
Compression levels explained
- Low compression (best quality): images re-encoded at 90% quality, no resolution reduction. File size drops 30-50% for image-heavy PDFs.
- Medium compression (balanced): 75% quality, max 200 DPI. File size drops 50-70%. Visually indistinguishable from original on screen.
- High compression (smallest file): 60% quality, max 150 DPI. File size drops 70-85%. Acceptable for archival but visible quality loss when zoomed in.
When to compress a PDF
Indian government portals (Income Tax India, Passport Seva, e-Mudhra) typically cap PDF uploads at 2-5 MB. A scanned passport photocopy from a typical Indian scan-shop is often 15-25 MB — too large for upload. Compress to medium first, check the size, drop to high if needed. Banking portals often have stricter limits (1-2 MB) for KYC document uploads. Email attachment limits in Gmail (25 MB), Outlook (20 MB), and most corporate email systems also benefit from compressed PDFs.
Limitations
Heavy compression on text-only PDFs may make text harder to read but won't reduce file size much. PDFs with embedded fonts already optimised cannot be compressed further by this tool. Encrypted PDFs cannot be compressed; decrypt first.
Disclaimer
Compression is lossy for embedded images. Always keep your uncompressed original. For legal documents, contracts, or anything where exact image fidelity matters (signature verification, fingerprint scans), use the lowest compression that fits your size requirement. Never compress and discard the original.
FAQ
Will the text still be selectable?
No. This tool flattens pages into images. If you need to keep text selectable, look for "lossless" or "structural" PDF compression — those need server-side tools.
How much smaller will my file be?
Typical reduction is 40–80% for image-heavy PDFs and 10–30% for text-heavy ones. Try Medium first; switch to High if you need more savings.
Is my PDF private?
Yes. Compression happens entirely in your browser using pdf.js and pdf-lib.
Frequently asked questions
What's the maximum PDF size I can compress?
The tool handles PDFs up to 100 MB. Larger files may slow your browser tab — close unrelated tabs first or split the PDF.
Will text become harder to read after compression?
No. Text in PDFs is stored as text (not as an image), so it's never re-compressed. Only embedded images are affected by the quality slider.
Why didn't my text-only PDF shrink?
Text-only PDFs are already very compact. There's little room to compress further. The tool's biggest gains come from PDFs with embedded scanned pages or photos.
Can I compress encrypted PDFs?
No. Decrypt first, then compress.
Can I batch-compress multiple PDFs?
Currently the tool processes one PDF at a time. For batch use, run the tool on each file in turn.