That Dreaded "Attachment Too Large" Message
We've all seen it. You hit send on an important email, and Gmail (or Outlook, or whatever) tells you your attachment is too big.
Most email providers cap attachments at around 25MB. Which sounds like plenty until you're dealing with a scanned contract, a presentation with images, or basically any PDF created from photos.
Here's how to fix it without losing your mind.
The Fast Fix
Our PDF Compressor can usually solve this in under a minute:
- Upload your oversized PDF
- Pick Medium compression (a good starting point)
- Download your smaller file
- Try attaching again
Nine times out of ten, that's all you need. Done.
But What If It's Still Too Large?
Sometimes a PDF is so big that even compression isn't enough. I've dealt with scanned documents that were 150MB — compression helped, but not enough to hit that 25MB email limit.
Here are your options:
Compress harder. Try Strong compression instead of Medium. You'll lose some image quality, but for many documents that's acceptable.
Split the PDF. Use our PDF Splitter to break the document into smaller pieces. Send them as separate attachments or as multiple emails.
Share a link instead. Upload to Google Drive, Dropbox, or OneDrive and just email the link. For really large files, this is often the cleanest solution anyway.
Why PDFs Get So Big
Understanding the problem helps. PDFs balloon in size mainly because of:
- High-resolution images — Photos and scans at 300+ DPI add up fast
- Embedded fonts — Some PDFs include complete font files
- Scanned pages — Each page is essentially a large image
Text-only PDFs are tiny. Image-heavy PDFs get massive. That's just how it works.
Typical Compression Results
To set expectations, here's what I typically see:
- A 30MB PDF usually compresses to around 10-15MB
- A pure scan might drop from 50MB to 15-20MB
- Text-heavy documents with few images might only shrink 10-20%
Strong compression gets more aggressive but can make images look a bit blurry. For documents that only need to be read on screen (not printed), usually not a problem.
Gmail Specifically
Gmail's 25MB limit is for the email including attachments. Meaning you have slightly less than 25MB for the actual file after headers and encoding overhead.
If your file is exactly 24.9MB, it might still bounce. Aim for a buffer — 20MB is a safer target.
The Sharing Link Alternative
For files over 25MB, honestly, a sharing link is often better anyway:
- No compression quality loss
- Works for any file size
- Recipient can download whenever convenient
- Most cloud services offer free tiers
Google Drive gives you 15GB free. That's a lot of PDFs.
Try It Now
Got a PDF that's giving you trouble? Head to our compressor and shrink it down.
Free, no account needed, and your files stay private on your device.
Want more control over your PDFs? Check out our guides on splitting PDFs and merging documents.