CookPDF
Compress PDF right on your device

Compress PDF online to reduce file size

Reduce PDF file size while optimizing for maximal quality

Select or drop a PDF file

Select PDF file

PDF files only

Max 100 MB

🔒 Secure connection · Auto-deleted after processing · Free

  • Strong size reduction
  • Preserve quality
  • Batch compression

Processed on your device

Files are not uploaded to CookPDF servers

The main operation runs in the browser on your device.

Keep the original

You should save the original file before changing the page structure or document quality.

Check the result

Review the order, page count, quality, and signatures before using the new file.

How to compress PDF

Follow three steps and check the new file before using it.

  1. Choose PDF

    Open the file you want to shrink and note its original size.

  2. Choose a compression level

    Balance the output size against the image quality you want.

  3. Review and download

    Compare the sizes, zoom in on important pages, then save the result.

Highlights

Useful capabilities for the right task on PDF documents.

Reduce size for sharing

Create a file that is easier to email or upload to a document portal.

Choose the compression level

Adjust based on whether you prioritize quality or size.

Check before using

Compare the resulting file with the original before replacing it.

Processed on your device

The main compression operation happens in your browser.

Use cases

Common situations for arranging or optimizing PDFs.

  • Send PDFs by email

    Reduce the size so the file fits better within email attachment limits.

  • Upload documents to online portals

    Create a lighter version before submitting records or uploading to a system with size limits.

  • Save storage space

    Reduce the size of documents kept long term, but still check the quality afterward.

Ready to compress your PDF?

Choose your PDF files to get started and check the result right in your browser.

Compress PDF

Compress PDF online to reduce file size

Reduce PDF size to make sending, uploading or storing easier, with the amount of reduction depending on the images, fonts and structure of the original file.

When should you use it?

  • Sending a PDF by email: Reduce the risk of exceeding attachment limits.
  • Uploading to online forms: Bring the file closer to the receiving system's size limit.
  • Saving storage space: Reduce the size of image-heavy documents when the output quality is still acceptable.

Recommended workflow

Keep the original file, set up the task on the preview and check every affected page before downloading. For documents used for signing, printing or official release, open the resulting file in another PDF reader to verify.

Limits to keep in mind

There is no fixed reduction ratio for every PDF. Files that are already optimized or mostly text may shrink very little; heavy compression can make images, scanned text or graphics look less clear.

Data and sessions

The main operation runs on your device and files are not uploaded to CookPDF servers. Your browser may keep a local cache to restore the session; you can clear the session in the interface or clear website data in your browser settings.

Frequently asked questions

Information about results, limitations, and how files are handled.

How much size can a PDF save?
The reduction depends on the content and structure of the original file. Image-heavy documents can usually shrink more than already-optimized files.
Does compression blur the text?
Vector text usually keeps its clarity better, but text inside a scanned image may lose quality under heavy compression.
Should I delete the original file after compressing?
Keep the original until you have thoroughly checked the resulting file.
Does compression affect digital signatures?
Rebuilding a PDF may invalidate an existing digital signature. Check after processing.

Ready to compress your PDF?

Choose your PDF files to get started and check the result right in your browser.

Compress PDF

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