WrenPDF

Compress PDF

Shrink a PDF right in your browser. You choose the quality and the resolution.

What it does

Email providers cap attachment size (Gmail and Outlook stop at around 20 to 25 MB), and scanned or photo-heavy PDFs blow past that easily. This tool re-encodes each page at the resolution (DPI) you choose, which often shrinks the file dramatically, and shows the old and new size side by side before you download.

There is a trade-off and we say it up front: pages become images, so the text can no longer be selected or searched. For scans that is no loss, because there was no selectable text to begin with. For contracts you need to copy from, pick a higher DPI or keep the original.

How to use it

  1. Drop your PDF file.
  2. Choose the target resolution (DPI) and JPEG quality.
  3. Press "Compress and download" and compare the new size.

When is it useful?

  • Shrinking scanned documents that are too big to email
  • Meeting upload limits on job, university or government portals (often 2, 5 or 10 MB)
  • Making a catalogue or photo PDF small enough to send on WhatsApp
  • Saving space in an archive of scans

Tips

  • For documents read on screen, 100 to 120 DPI at medium quality is usually plenty.
  • For anything you will print, do not go below 150 DPI or small text may blur.
  • If the result is bigger than the original, your file was already well compressed. Keep the original.

Frequently asked questions

Can the text still be selected?
No. This tool converts every page into an image and re-encodes it; that is the most effective way to shrink a file, but the text can no longer be selected or searched. It is ideal for scanned or image-heavy PDFs: use it with care on text-heavy documents.
Which DPI and quality should I choose?
For screen or email use, 100-120 DPI at medium quality is usually enough. If you want to preserve print quality, choose 200 DPI at high quality.
What if the file gets bigger after compression?
With PDFs that are already heavily compressed or that have few simple pages, this tool can make the file larger; in that case, keep using your original file.
Can I compress several PDFs at once?
Yes. Open Batch Processing, choose Compress and drop all your files; the results come back as one ZIP.
How much smaller will my file get?
It depends on the document. High-resolution scans often shrink several times over; short, text-heavy PDFs may gain little or nothing.

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