Almost every email provider caps attachment size somewhere between 10 and 25 MB, and scanned documents blow past that limit constantly — a phone camera can produce a 50-page scan well over 100 MB without anyone intending it. Before you resort to a file -sharing link, it's worth trying compression first.
Why PDFs get so large in the first place
In the vast majority of oversized PDFs, the culprit is images: a scanned page saved at full camera resolution, a screenshot pasted in at 3x the size it's displayed, or a photo embedded without any downsampling. Text itself takes up very little space — a 300-page novel in PDF form is often smaller than a single high-resolution scanned page.
How to compress a PDF in your browser
- Open the Compress PDF tool and upload your file.
- Pick a quality level: High quality for light compression, Balanced for most everyday use, or Smallest size when you need to hit a strict limit.
- Click Compress PDF and wait for it to process each page.
- Check the reported new size, then download.
What to expect
This kind of compression re-renders each page as an image at your chosen quality and rebuilds the PDF around it — the same underlying technique most compression tools use for scanned or image-heavy documents. It's extremely effective on scans and photo-heavy files, often shrinking them by 70–90%. It's less useful on PDFs that are already mostly text with no embedded images, since there's little left to compress; in that case the file was probably small enough to email already.
The trade-off worth knowing
Because compression converts each page into an image, text in the compressed file is no longer selectable or searchable. If you need to keep text editable and searchable while still reducing size, your best options are removing unnecessary embedded images manually or accepting a smaller size reduction. For sending a document to be read rather than edited — which covers most email attachments — that trade-off is usually a non-issue.