Compress PDF Files Online
Reduce the size of one or more PDF files before sharing, storing, or attaching them. Compression runs in your browser and offers low, medium, and high settings.
Reduce PDF file size in your browser
QPDF optimizes document streams and eligible images while keeping PDF text and vector content intact.
Private by design · Files stay on your deviceor choose PDFs from your device
Multiple files · Up to 100 MB eachPDFs are processed locally in a Web Worker; your documents are never uploaded. Compression can reduce embedded image quality at higher levels, while text stays selectable. Files already optimized may not get smaller. Rewriting a digitally signed PDF invalidates its signature.
What you can do with this tool
- Accepts PDF files up to 100 MB each.
- Process multiple PDFs and download individual files or a ZIP archive.
- Choose low, medium, or high compression depending on the balance you need.
How to use PDF Compressor
- Select or drop one or more PDF files.
- Choose a compression level for the balance between size and quality.
- Start compression, then download each PDF or the completed ZIP archive.
When this tool is useful
- Reduce an image-heavy PDF before attaching it to an email or form.
- Prepare documents for storage when the original file is larger than needed.
Limits and privacy
Compression results depend on the PDF. Image-heavy documents are more likely to shrink than files made mostly of text, and high compression can affect embedded image quality. Files are processed in your browser; each input can be up to 100 MB.
Frequently asked questions
Does compression change the PDF text or pages?
The tool preserves the document pages and text while optimizing PDF content. Image-heavy documents usually show the largest size reduction.
Is there a PDF upload limit?
Each PDF can be up to 100 MB. A combined ZIP download is limited to 500 MB.
Are my PDFs sent to a server?
No. The compressor uses a browser worker and processes selected PDFs on your device.