Compress PDF Online

Reduce file size while maintaining quality.

✓ Free   •   ✓ Secure   •   ✓ No Watermark

Use this tool to shrink large PDF files for email, uploads, and faster sharing. Compression works by optimizing images and internal resources inside your PDF so the document loads quicker and uses less storage. For most files, Recommended gives the best balance between clarity and size savings.

After compression, you can download each file separately or use Download All when multiple PDFs were uploaded. Need more PDF tools? Try Merge PDF, Split PDF, PDF to Word, or Word to PDF. For best practices, see our guide: Compress PDF without losing quality.

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Extreme is best when you need the smallest file for uploads or email limits. Recommended is ideal for most PDFs like invoices, reports, forms, and eBooks. Low keeps the best visual quality when images and sharp text matter.

For best privacy, avoid uploading highly sensitive documents on public/shared computers. Download your compressed files immediately after processing.

How to Compress PDF Files

PDF compression helps reduce the size of large documents by optimizing embedded resources (like images) and removing unnecessary overhead. Smaller PDFs upload faster, share easier, and often meet strict file-size requirements for email, job applications, school portals, and government forms.

  1. Click Select PDF Files and upload one or more PDF documents.
  2. Choose a compression level. Recommended is the best option for most users.
  3. Click Compress PDF. When complete, download each file or use Download All.

When should you compress a PDF?

Compressing is useful when your PDF is too large to email, too big for a website upload, or slow to open on mobile. It’s also helpful for archiving and saving storage. If your PDF contains many high-resolution images, compression can produce the biggest reduction.

  • Email attachments: reduce file size to meet mailbox limits.
  • Online forms & portals: many systems reject files above a certain size.
  • Website downloads: smaller PDFs load faster for visitors.
  • Mobile sharing: send lighter files over slower connections.

Related PDF tools you can use next

After compression, you may want to combine pages, convert formats, or generate a QR code to share your file quickly. Here are popular tools available on PDFConvertPrime:

FAQ

Will compression remove pages or text?
No. Compression is designed to keep the document structure the same. It primarily optimizes resources such as images.

What if I don’t see a size reduction?
Some PDFs are already optimized. Try a stronger compression level or consider converting to images and back to PDF if appropriate.

Can I compress scanned PDFs?
Yes. Scanned PDFs often contain large images, so they typically compress well. Use Low compression if you need maximum readability.