Compress PDF
Rewrite PDF structure locally in your browser. Files with structural redundancy may shrink; otherwise the original is kept. Files are not uploaded to SnapshotLab.
Click to choose PDFs or drag them here
PDF only · Up to 20 files
Files stay on your device and are never uploaded.
How to use
- 1Choose PDFsClick the upload area or drop up to 20 PDF files at once.
- 2CompressStart compression and each file is structurally rewritten on your device.
- 3Download resultsDownload each compressed PDF or save all successful results in one ZIP.
About PDF compression
This browser-based tool rewrites PDF structure and saves with object streams while preserving pages and page content. Files with redundant objects or inefficient structure may shrink, but the result depends on the source and no fixed reduction is promised.
JavaScript in your browser processes the file on the current device instead of uploading the PDF to SnapshotLab. If the re-saved file is not smaller, the tool returns the original and reports that it cannot be reduced further.
Which PDFs may become smaller?
This tool targets structural redundancy. PDFs repeatedly saved by some editors or containing inefficient object structures may shrink. Already optimized files and PDFs dominated by photos or scans usually see limited benefit because images are not re-encoded and fonts are not subsetted.
Common uses
- Try removing rewritable structural overhead before sharing and review the exact savings.
- Check a batch of PDFs while preserving originals that cannot be made smaller.
- For a larger reduction, remove unnecessary pages or optimize source images first.
If you need only part of a document, split the PDF or use page organizer to remove unnecessary pages. Compare more methods in How to Reduce PDF File Size.
Frequently asked questions
QWill my PDFs be uploaded to a server?
No. Compression happens entirely in your browser. Your files never leave your device, and we cannot access them.
QWill compression reduce PDF quality?
Images are not recompressed and content is not removed. The tool rewrites the document structure and uses object streams and Flate compression while preserving every page.
QWhy does a file say it cannot be reduced further?
The PDF may already be optimized. If rewriting does not make it smaller, the original is kept so the result never becomes larger.
QHow many PDFs can I compress at once?
Up to 20. Each is processed independently, so one failure does not affect the others.
QHow do I download compressed files?
Download a single successful PDF directly, or package multiple results into one ZIP.
QDo I need to sign up or pay?
No. The tool is free, requires no account, and adds no watermark.