Compress PDF

Reduce PDF file size in your browser — lossless clean-up or strong compression for scanned PDFs. No upload.

How do I reduce the size of a PDF?

Choose the PDF and a compression level, then press Compress. Lossless mode rebuilds the file with compressed object streams, while Low, Medium and High re-render each page as an optimised image, which can make scanned or image-heavy PDFs 50–90% smaller.

Which level should I choose?

Level	Best for	Text selectable?
Lossless	Text documents, forms, reports	Yes
Low (150 DPI)	Scans you may print	No
Medium (110 DPI)	Email attachments, uploads with size limits	No
High (80 DPI)	Smallest possible file for screen reading	No

If the result would be larger than your original, the tool tells you and keeps the original — some PDFs are already optimised. Everything happens on your device, so confidential files never leave it.

Frequently asked questions

Why is my compressed text not selectable?

Low, Medium and High turn pages into images to save space. Use Lossless to keep text selectable and searchable.

Is my PDF uploaded?

No, compression runs in your browser with pdf.js and pdf-lib.

How small can it get?

Scanned PDFs often shrink by 70–90% on Medium. Text-only PDFs are already small and change little.