PDF Compressor Online

Compress PDF files online for free. Reduce PDF file size directly in your browser without installing software.

How to use it

1

Upload your PDF. Drag and drop your PDF into the upload area or choose a file from your device.

2

Choose compression. Select Recommended, Smaller File, or Maximum Compression depending on your needs.

3

Compress your PDF. Click Compress PDF and wait while the document is processed in your browser.

4

Download the result. Check the new file size and download your compressed PDF.

What's supported

  • Image-heavy PDF documents
  • Scanned PDF documents
  • Multiple compression levels
  • PDF size comparison
  • First-page PDF preview
  • Drag and drop upload
  • Browser-based processing

×Not ideal for

  • Text-heavy PDFs where preserving selectable text is important
  • Documents requiring lossless image compression
🔒

Your PDF is processed in your browser. The compressor renders and rebuilds the document on your device rather than requiring a server upload.

Compress PDF Online for Free

Compress PDF files online with DommyTools. Reduce the size of large, scanned and image-heavy PDF documents for easier sharing, uploading and storage. Choose the compression level that best matches your required file size and image quality.

What Is a PDF Compressor?

A PDF compressor reduces the file size of a PDF document by rendering its pages at a selected resolution and rebuilding them as optimized images. This can be particularly useful for scanned documents, photographed documents and PDFs containing many large images.

How to Compress a PDF Online

  1. Upload or drag and drop your PDF.
  2. Choose a compression level.
  3. Click Compress PDF.
  4. Wait while your document is processed.
  5. Compare the original and compressed file sizes.
  6. Download your smaller PDF.

PDF Compression Levels

Recommended Compression

A balanced option for reducing PDF size while maintaining good image quality and readability.

Smaller File

Provides stronger compression when reducing file size is more important than maximum image quality.

Maximum Compression

Designed for situations where you need the smallest possible output file size.

Image-Heavy PDFs

Compression generally works best with PDFs containing scanned pages, photographs and other large images.

Why Compress a PDF?

  • Reduce PDF file size for email attachments.
  • Make large documents easier to upload.
  • Save storage space on your device.
  • Share scanned documents more easily.
  • Reduce the size of documents for websites and online forms.
  • Make image-heavy PDF files easier to transfer.

When Should You Compress a PDF?

PDF compression is especially useful when a document contains high-resolution scans, photographs or many embedded images. A smaller PDF can be easier to email, upload to online portals, store in cloud services and share with other people.

Frequently Asked Questions

Is this PDF compressor free?

Yes. DommyTools provides a free online PDF compression tool.

Can I compress a scanned PDF?

Yes. The compressor is particularly suitable for scanned and image-heavy PDF documents.

Will PDF quality decrease?

Compression can reduce image quality. Higher compression settings generally produce smaller files but may make images less detailed.

Which compression level should I choose?

Recommended is a good starting point for most documents. Choose Smaller File or Maximum Compression when reducing the file size is the priority.

Does the PDF compressor work on mobile?

Yes. The interface is designed to work in modern desktop and mobile browsers.

Are my PDF files uploaded to a server?

The compression process in this tool runs in your browser. Your PDF does not need to be uploaded to a server for the compression operation.

Can compression make a PDF larger?

Yes. Some already-optimized or text-heavy PDFs may not become smaller after being rebuilt as images. The tool shows the original and compressed sizes so you can compare the result.