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Compress PDF

Reduce your PDF file size for email, web, or archiving. Choose your quality level and download in seconds. Files are automatically deleted within 60 minutes.

UPDF — AI-Powered PDF Editor

Compress Your PDF

Choose a quality level, select your file, and click Compress. Your file is uploaded, processed by Ghostscript, and ready to download in seconds.

Server-Side Tool — This operation is performed on our secure servers. Files are automatically deleted within 60 minutes. Prefer not to upload? Adobe Acrobat Pro compresses locally.
Drop your PDF here
or click to browse — max 50MB
PDF Max 50MB
Selected File
PDF
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Compression Quality
Compressing your PDF…
Uploading and processing — this usually takes a few seconds
File Size Reduction
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Original: —
Compressed: —

How PDF Compression Works

PDFToolShack uses Ghostscript — the industry-standard open-source PDF processor — to reprocess your PDF and reduce its file size. Ghostscript resamples images, removes embedded thumbnails, and optimises the PDF content stream based on the quality level you choose.

The Ebook setting is recommended for most users — it reduces file size significantly while keeping text sharp and images clear enough for most purposes. Use Screen for the smallest possible file when print quality doesn’t matter, or Printer/Prepress when you need to maintain high-resolution images for professional output.

Results vary depending on the content of your PDF. Image-heavy PDFs typically see 40–80% size reduction. Text-only PDFs may see little or no reduction since text is already very compact in PDF format.

Frequently Asked Questions

Is my file secure when uploaded?
Yes. Your file is transferred over HTTPS, processed immediately, and automatically deleted within 60 minutes. It is never stored permanently, shared with third parties, or used for any purpose other than compression. No account or login is required.
Why is this tool server-side when others aren’t?
PDF compression with Ghostscript produces far better results than JavaScript-based compression — it can resample images, remove redundant data, and optimise the entire PDF structure. This level of processing requires a full software stack that can only run on a server, not in a browser.
Which quality setting should I use?
Ebook (150 DPI) is the best choice for most people — great for email attachments, web uploads, and general sharing. Use Screen only when file size is critical and quality is not. Use Printer or Prepress when you need to maintain high-resolution images for professional printing.
Why didn’t my file get smaller?
Text-only PDFs (contracts, reports, letters) are already very compact and may not compress further. PDFs that were already compressed by another tool, or PDFs with very low-resolution images, may also see little reduction. Image-heavy PDFs typically see the greatest size reduction.
Is there a file size limit?
The maximum file size is 50MB. For larger files, consider splitting the PDF first using our Split PDF tool, compressing each part, then merging them back together.
How long until my file is deleted?
Your file is automatically deleted within 60 minutes of processing — usually much sooner since it’s deleted immediately after you download it. If you don’t download within 60 minutes, it is deleted automatically regardless.