Reduce PDF file size by repacking its internal structure and stripping metadata. Free, browser-based — your PDF never leaves your device.
How PDF compression works
The tool loads your PDF in the browser and re-saves it using object streams — a more compact way of packing the PDF's internal objects. It also strips metadata such as author name, title, and producer information. The visual content — text, images, layout — stays exactly the same. Because the process is lossless, your document looks identical; it's just stored more efficiently.
Which PDFs compress well?
- Older exports and scanned documents — PDFs from older software often store their objects loosely, so repacking can shrink them noticeably
- PDFs with lots of metadata — files carrying author, producer, and revision data get trimmed
- Multi-tool PDFs — documents saved and re-saved by several apps often accumulate redundant structure
Modern PDFs from Chrome's "Print to PDF" or recent Adobe Acrobat versions are already tightly packed, so they may shrink very little — or not at all. When that happens, the tool keeps your original file unchanged rather than handing back anything larger. For image-heavy scans where you need a big reduction, compressing the source images first with the image compressor before creating the PDF gives the largest savings.
Frequently Asked Questions
How does the PDF compressor work? +
It re-saves your PDF using object streams — a compact way of packing the file's internal objects — and strips metadata like author, creator, and timestamps. The visible content stays identical because the process is lossless.
How much can a PDF be compressed? +
It depends entirely on the file. PDFs from older software or with loose internal structure can shrink meaningfully; modern, already-optimised PDFs may shrink only slightly or not at all. If no reduction is possible, your original file is kept unchanged.
Does compression affect PDF quality? +
No. This is lossless — it repacks the file's structure and removes metadata only. Text, images, and layout remain unchanged.
Is my PDF uploaded to a server? +
No. The PDF is processed entirely in your browser. Your file never leaves your device.