“Attachment too large” usually means your PDF exceeds the provider’s per-message limit—or a corporate gateway that is stricter than consumer Gmail. Compressing client-side keeps drafts and contracts on your device while you chase a size that will actually send.
Official & common attachment ceilings
| Provider | Typical limit | Notes / source |
|---|---|---|
| Gmail (personal) | 25 MB total attachments | Google Gmail Help — attachments |
| Google Workspace | Admin-defined (often 25 MB; some editions higher on web) | Ask your admin; do not assume consumer limits |
| Outlook.com | ~20 MB | OneDrive link fallback common |
| Corporate / Exchange | Often 5–10 MB | Gateway policies vary widely |
| Apple iCloud Mail | ~20 MB | Mail Drop for larger items |
Always confirm in the product’s help center—limits change by account type.
How to compress a PDF for email
- Open Compress PDF.
- Upload the file and note the starting size.
- Use medium quality for mixed text/images; stronger compression for text-only reports.
- Download and check the OS file size (Base64 encoding in transit can expand payload slightly—leave headroom).
- Attach and send a test to yourself if the document is critical.
Strategy by content type
Text reports & contracts
Born-digital text usually shrinks dramatically. Aggressive compression rarely harms readability. Name the
file clearly (Invoice_2026-Q3.pdf) so recipients trust the attachment.
Decks with photos
- Compress source images with Compress Image before exporting PDF
- Drop unused high-DPI screenshots
- Prefer medium compression to avoid blocky slides
Scans
Camera/scanner PDFs dominate “won’t go under 25MB” tickets. Re-scan at 150 DPI grayscale when color is not required, or follow compress scanned documents.
If compression is still not enough
- Split: Split PDF and label Part 1/2/3.
- Cloud link: Drive / OneDrive / Dropbox—Gmail may insert Drive automatically over 25MB.
- Portal instead of email: for government forms use government PDF guide (100–200KB targets).
Cluster links
Ready to send?
Use Compress PDF, leave a few MB of headroom under your provider’s documented limit, and cite Gmail’s attachment help when arguing policy with non-technical teammates.