How to Compress a PDF to Reduce File Size
Big PDF files are a hassle — they bounce back from email limits, upload slowly, and eat storage. Compressing a PDF reduces its size so it's easier to share, while keeping it perfectly readable. This is especially effective for scanned documents and image-heavy PDFs.
Why PDFs get so large
Most of a PDF's size comes from images and scanned pages, which store far more detail than a screen needs. By re-rendering those pages at a sensible quality, you can cut the file size dramatically without any visible difference for everyday viewing.
Step-by-step: compress a PDF
- Open the Compress PDF tool.
- Upload your PDF by dragging it in or clicking to browse.
- Choose a quality level — 70% is a good balance of size and clarity.
- Click Compress PDF and compare the original vs new size.
- Download the smaller file.
Which PDFs compress best?
Scanned documents and PDFs full of photos shrink the most. A PDF that is mostly plain text is already small, so the savings there are smaller. If a compressed file looks too soft, simply redo it at a higher quality.
Frequently Asked Questions
Will compression ruin the quality?
At moderate settings the difference is barely noticeable on screen. You control the quality with a slider, so you decide the balance.
Why did my text-only PDF barely shrink?
Text PDFs are already efficient. Compression mainly helps image-heavy or scanned files.
Is my file uploaded to a server?
No. Compression happens entirely in your browser, so your document stays private.
What size should I aim for?
For email, under 10 MB is usually safe; many forms want under 2 MB. Check the result and adjust quality as needed.
Is it free?
Yes, completely free with no watermark or sign-up.
Try the Compress PDF Tool