Is it safe to compress my PDF online?

Yes. FileKit processes your file entirely in your browser — nothing is uploaded to any server. Your document never leaves your device, making it safe for contracts, medical records, and other sensitive files.

How much smaller will my PDF get?

Typical savings are 20–60% for office-exported PDFs. Files with large embedded images see the biggest reduction. The 'Rasterise' option can achieve 80%+ reduction but converts text to images.

Will compression affect print quality?

The 'Low' and 'Balanced' levels preserve full print quality. 'Strong' slightly reduces image sharpness but remains suitable for most uses. 'Rasterise' converts pages to 150 DPI images — fine for screen but not ideal for high-quality printing.

Can I compress a password-protected PDF?

You need to unlock the PDF first. Use our Unlock PDF tool to remove the password, then compress the file.

Is there a file size limit?

There is no hard limit, but very large PDFs (over 200 MB) may be slow to process since everything runs in your browser. For best performance, we recommend files under 100 MB.

What makes a PDF file large?

Embedded high-resolution images, fonts, annotations, and metadata are the main drivers. PDFs with scanned pages are often 10-50x larger than text-based ones.

Does compression remove pages or content?

No. Compression reduces image resolution and optimises internal structures, but all pages, text, and layout remain intact.

Can I compress multiple PDFs at once?

Yes. You can drop several files onto the tool and compress them in one batch. Each file is processed independently in your browser.

Compress PDF

Your files never leave your device

Compression level

Drop files here

or click to browse

Max 500.0 MB per file·Supports: PDF

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🧩

Merge PDF

Combine multiple PDFs into a single file, in any order

✂️

Split PDF

Extract pages by single page or custom ranges

🖼️

PDF to Images

Export every page as a JPG or PNG image

How PDF compression works

FileKit compresses your PDF entirely in the browser using advanced optimization techniques. Images within the PDF are resampled and recompressed, while fonts and metadata are optimized. Since everything runs locally, your files never leave your device — perfect for sensitive documents.

How to Compress a PDF

1
Upload your PDF
Drag and drop your PDF file into the upload area, or click to browse your files. Your file stays on your device — nothing is uploaded to any server.
2
Choose a compression level
Select from four options: Low (lossless, structure only), Balanced (recompresses images), Strong (aggressive image compression), or Rasterise (converts pages to images for maximum reduction).
3
Review the result
FileKit shows you the original and compressed file sizes, along with the percentage saved. If the file was already well-optimised, you will be notified.
4
Download the compressed PDF
Click the download button to save the smaller PDF to your device. The original file is never modified.

Compress PDF

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How PDF compression works

How to Compress a PDF

Upload your PDF

Choose a compression level

Review the result

Download the compressed PDF

Frequently Asked Questions

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