How to Compress a PDF to Reduce File Size

Large PDFs are a pain — they fail to email, take forever to upload, and clog up storage. But nobody wants a blurry, unreadable compressed file either. Here's how to shrink a PDF while keeping it sharp.

What actually makes PDFs large?

PDFs get big for a few reasons:

• Embedded images — scanned pages or high-res photos are the biggest culprit
• Embedded fonts — full font files baked into the PDF
• Metadata and thumbnails — version history, comments, and preview images
• Uncompressed objects — PDFs created from certain apps with no optimization

How to compress without ruining quality

The key is choosing the right compression level for your use case:

For most use cases — emailing a scanned document, uploading to a portal — Recommended quality is fine. RizzPDF recompresses only the embedded raster images (photos, scans) inside your PDF. Text, fonts, and vector graphics are never touched, so text stays fully selectable and searchable in the output.

Step-by-step: compress a PDF free

1. Open RizzPDF Compress PDF
2. Drop your PDF onto the page
3. Choose a compression level (Screen, eBook, or Printer)
4. Click Compress and download

Your file is processed securely and never stored.

Why is my PDF still large after compressing?

If your PDF contains mostly text and vectors with few embedded images, there is less to recompress and savings will be modest. In that case, removing unnecessary pages is often a better approach. For image-heavy PDFs — scans, brochures, reports with photos — you can expect significant size reduction.

Email size limits by provider

• Gmail: 25MB attachment limit
• Outlook: 20MB attachment limit
• Yahoo Mail: 25MB attachment limit

If your PDF exceeds these limits, compressing to Screen quality usually brings it well under 10MB.