Compress PDF

Q: Will compression reduce PDF quality?

No. This tool removes unused objects and optimizes the file structure without touching the visible content. Text, fonts, and images remain unchanged.

Q: What is the best way to compress a PDF?

For the best results, use the Strong compression setting. If your PDF was created by scanning, the reduction may be modest since the images are already compressed.

🔒 Your files never leave your browser. 100% private. Zero upload.

Related Guides

Want to go further? These step by step guides cover it in detail.

How to Compress a PDF·How to Reduce PDF File Size·How to Compress a PDF for Email

Honest note: This tool removes unused data and optimizes the PDF structure. For heavy image-based PDFs, size reduction may be modest (5-30%). For text-heavy PDFs, results are typically better. Deep image recompression requires server-side processing, which would mean uploading your file. We don't do that.

📦

Drop your PDF here

or click to browse

How to Compress a PDF

📂

Drop your PDF

Drag your PDF onto the box or click to select it from your device.

⚙️

Choose level

Pick a compression level. Medium is recommended for most files.

⬇️

Download result

See the size reduction and download your smaller PDF.

Tested verdict:

Best for: Getting a PDF portfolio under a 5MB email attachment limit, and slimming a text-heavy report before sending it to a client

Limitations: Removes unused data and optimises structure, so text-heavy files shrink well but image-heavy scans typically drop only 5 to 30 percent, and it does not recompress images deeply

Best suited for: Office staff whose attachment keeps bouncing back for exceeding a mailbox size limit

Frequently Asked Questions

How much can I reduce a PDF file size?

Results vary. Text-heavy PDFs with unused metadata can see 10-40% reduction. Image-heavy PDFs may see 5-20% with this browser-based tool, since deep image recompression requires server-side processing.

Will compression reduce PDF quality?

No. This tool removes unused objects and optimizes file structure without touching visible content. Text, fonts, and images remain unchanged.

What is the best way to compress a PDF?

Use the Strong compression setting for maximum reduction. If your PDF was created from scanned images, the reduction may be modest since the images are already compressed within the file.

Why is my compressed PDF similar in size?

If the PDF was already optimized or consists mainly of compressed images, there is little unused data to remove. This is a known limitation of client-side compression, and we are upfront about it.

Can I compress a PDF without losing text quality?

Yes. This tool does not alter text or fonts. Text remains fully readable and searchable after compression.

Understanding PDF Compression

PDFs get large primarily because of embedded images and fonts. A single scanned page at 300 DPI can be 500 KB to 2 MB depending on color depth. Images account for 80-90% of PDF size in most documents. Lossless compression preserves exact pixel data and suits text-heavy documents; lossy compression discards some image detail and works better for photographs. Email servers typically reject attachments over 25 MB, and many document platforms cap uploads at 10 MB. Compressing before sending avoids rejections. Example: a 40-page scanned contract at 8 MB typically compresses to 2-3 MB at moderate quality settings with no visible text degradation. Files are never uploaded - all processing stays local in your browser.

How Does PDF Compression Work?

Most of the weight in a typical PDF is images rather than text, so compression targets them first. The tool parses the document, locates embedded image streams, and re-encodes them at a lower resolution or a higher lossy compression ratio. Text and vector content are left alone, because they are already stored as instructions rather than pixels and compress poorly by comparison. Unused objects and duplicate resources are dropped, and the cross reference table is rewritten for the smaller file.

This is why results vary so widely. A text heavy report may barely shrink, while a document built from phone photos can lose most of its size with no visible change. The stream and object structures being rewritten are described by the PDF Association overview of the format.

When Should You Use PDF Compression?

The usual trigger is an email or upload limit. Most mail providers cap attachments at around 20 to 25 MB, and many government or bank portals set far lower limits. Compression is also worth running before publishing a PDF on a website, since a large file is slow to open on mobile connections.

Skip it when the document must stay print ready or archival, since reducing image resolution is not reversible. Keep the original in those cases and compress a copy.