Compress PDF
Downsample and re-encode images, subset fonts, drop duplicates and repack the file — the same techniques the big online compressors use, running entirely in your browser. Your PDF is never uploaded.
How to Use
- Choose a compression level (Medium is recommended for most files).
- Drop or select your PDF.
- Download the compressed file.
Low — re-saves with object streams.
Medium — Low + strips document metadata (title, author, keywords, producer).
High — Medium + removes annotations, bookmarks, and named destinations.
FAQ
Why is the size reduction small?
This tool removes PDF structural overhead — redundant objects, metadata, cross-reference streams. It does not re-encode embedded images, which are usually the largest part of a PDF. For larger reductions on image-heavy files, re-encoding is required and must be done server-side.
Is my PDF uploaded?
No. Everything runs locally in your browser using pdf-lib.
How large can a PDF be?
Up to 1.2 GB per file, and 2 GB per batch. Because the work happens in the tab, a file that size needs a desktop browser with the memory free — expect several minutes, and close other heavy tabs first. On a phone, or if compression stops with a memory error, split the PDF and compress the parts.
Will High compression break my PDF?
Removing annotations and bookmarks is safe for most documents. If your PDF relies on interactive forms or bookmarks for navigation, use Medium instead.