How does PDF compression work?

The tool reduces image quality and removes unnecessary data from the PDF to decrease file size while keeping the document readable.

Will compression affect text quality?

No. Text remains sharp and crisp. Only embedded images are compressed.

How much can I reduce the file size?

Typically 30-70% reduction, depending on how many images the PDF contains. Text-only PDFs may see smaller reductions.

Are my files uploaded?

No. Compression happens entirely in your browser. Your files never leave your device.

Compress PDF

Reduce PDF file size by optimizing internal streams

Drop PDF here

or click to browse

Choose File

Frequently Asked Questions

What is Compress PDF?

Compress PDF is a free browser-based tool that reduces the file size of your PDF documents so they are easier to share, email, or store. Large PDFs with high-resolution images and embedded fonts can balloon in size, making them cumbersome to work with. This tool strips unnecessary metadata, optimizes internal structures, and re-encodes content to shrink the file while maintaining readable quality. Everything is processed locally using the pdf-lib JavaScript library, so your documents never leave your computer. No server upload means your private files stay private.

When to Use Compress PDF

Reach for this tool whenever your PDF is too large for its intended purpose. Common scenarios include:

Shrinking attachments to fit within email size limits (often 10-25 MB).
Reducing scanned document sizes before uploading to government or insurance portals.
Optimizing PDFs for faster loading on websites or content management systems.
Saving storage space when archiving years of invoices, reports, or receipts.
Preparing presentation handouts for distribution without taxing recipients bandwidth.

How It Works

Select or drag your PDF into the upload area. The tool reads the document entirely in your browser, analyzes its internal structure, and applies compression optimizations using pdf-lib. Once processing is complete, a smaller version of your file is generated and ready to download. Because no data is sent to a server, the tool works even when you are offline, provided the page has already loaded. There is no account creation, no watermark on the output, and no cost. Just pick your file, compress, and download.