How much can I reduce a PDF file size?

PDF compression varies depending on the content. PDFs containing many images can typically be reduced by 40–80%. Text-heavy PDFs usually compress by 10–30%. Our default 'eBook' quality preset provides an excellent balance — most PDF files compress by 30–60% with no visible quality difference.

Are my PDF files stored on your server?

No. Your PDF file is uploaded to our secure EU server (Slovakia), compressed using Ghostscript, and the compressed file is returned to your browser. The file is deleted from our server immediately after compression. We never store, analyze, or share your PDF files.

What is the difference between Screen, eBook, and Print quality?

Screen quality produces the smallest file size, targeting 72 DPI for images — ideal for PDFs that will only be viewed on screen and emailed. eBook quality targets 150 DPI — recommended for most use cases, providing a good balance of file size and readability. Print quality targets 300 DPI — ideal when you need to print the compressed PDF and want to preserve fine details.

Can I compress a PDF to under 100 KB?

It depends on the PDF content. For short, text-heavy PDFs, achieving under 100 KB is possible using the 'Screen' quality preset. For image-heavy PDFs, the final size depends on the number and size of images. Use the 'Screen' preset for maximum compression and check the resulting file size.

Is there a file size limit?

The free tool supports PDF files up to 50 MB. For larger PDF files, you can create a free Culacc account which supports files up to 100 MB. Most typical PDFs (presentations, reports, invoices) are well under this limit.

Why is my PDF file so large to begin with?

Large PDF files are usually caused by: high-resolution embedded images (photos, screenshots), embedded fonts, uncompressed content streams, or scanning at high DPI. Our compressor addresses all of these by resampling images to an appropriate DPI and applying efficient stream compression.

Does PDF compression affect the text quality?

No. Text in PDF files is stored as vector data and is not affected by compression. Only the embedded images are resampled. Your PDF text will remain perfectly sharp and searchable after compression.

Do I need an account to compress PDF files?

No account is required. The PDF compressor is completely free without any signup. If you want to store, organize, and share your compressed PDFs in the cloud, you can create a free Culacc account with 5 GB of storage.

Free · Secure EU Server · No Signup

Compress PDF Files
Securely Online

Reduce PDF file size by up to 80% without losing quality. Processed on our secure EU server and deleted immediately. Free, no account required.

Files deleted immediately

EU server — GDPR compliant

Up to 50 MB per file

No account needed

📄 PDF Compressor

Quality preset

Best balance of file size and readability

Secure EU server · Deleted immediately

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Drop your PDF here

PDF files up to 50 MB · Multiple files supported

Files are processed securely and deleted immediately

Compressing PDF...

Results

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Your PDF Files Are Processed Securely and Deleted Immediately

Your PDF is uploaded over an encrypted HTTPS connection to our server in Slovakia, EU — subject to strict GDPR data protection rules. The file is compressed using Ghostscript (an open-source PDF processor) and the compressed file is returned to your browser. Your original file and the compressed result are deleted from our server immediately after the response is sent. We never store, read, analyze, index, or share your PDF files.

How to Compress a PDF

Reduce PDF file size in 3 steps

No software to install. Works on Windows, Mac, and mobile. Files are processed securely and deleted immediately.

Upload your PDF

Drag and drop your PDF into the upload area or click "Choose PDF." Files up to 50 MB are supported. No account required.

Choose quality preset

Select "eBook" for the best balance of size and quality, "Screen" for the smallest possible file, or "Print" for high-quality output.

Download compressed PDF

Your PDF compresses in seconds. See the exact before and after file sizes, then download. The file is deleted from our server immediately.

Quality Presets

Which quality should I choose?

Choose based on how the PDF will be used.

Screen

Smallest File

Best for PDFs that will only be viewed on screen — websites, email attachments, sharing online.

72 DPI image quality

Smallest size

eBook ★ Recommended

Best Balance

Ideal for most use cases. Readable on screen and acceptable for home printing. Reduces file size significantly.

150 DPI image quality

Recommended

High Quality

For PDFs that need to be printed professionally. Preserves fine image detail. Less compression than other presets.

300 DPI image quality

Best quality

What Makes PDF Files Large — and How Compression Fixes It

Large PDF files are typically caused by high-resolution embedded images — screenshots, photographs, and scanned pages stored at print resolution (300+ DPI) even when only web viewing is needed. A single full-page screenshot can add 2–5 MB to a PDF.

Our PDF compressor uses Ghostscript, an industry-standard open-source tool, to resample embedded images to an appropriate resolution for the intended use case. For an "eBook" preset, images are resampled to 150 DPI — indistinguishable on screen but dramatically smaller in file size.

Importantly, text quality is never affected. PDF text is stored as scalable vector data, not as images, and is not touched by compression. Your text remains perfectly sharp and searchable after compression.

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