Compress PDF for Email
Shrink PDF attachments to fit Gmail, Outlook, and Yahoo mail limits.
Send PDFs by email without bounce-backs
Large PDF attachments are one of the most common reasons emails get rejected — silently. Your email client may show it was sent, but the recipient's server quietly discards it. This tool targets 10 MB, which clears every major email provider's hard limits with room to spare for base64 encoding overhead and other attachments.
Size limits for major email providers
- Gmail — 25 MB total per email (all attachments combined)
- Outlook / Microsoft 365 — 20 MB (shared across all attachments)
- Yahoo Mail — 25 MB per email
- Apple Mail / iCloud — 20 MB default; Mail Drop kicks in above that
- Corporate email servers — often stricter (5–10 MB is common)
Why 10 MB and not 25 MB?
Email attachments are base64-encoded in transit, which adds roughly 33% to the actual payload size. A 25 MB PDF becomes ~33 MB on the wire — exceeding the server limit even though your client shows it as 25 MB. Targeting 10 MB keeps the on-wire size under 14 MB, well inside every provider's limit and most corporate filters. If you're sending to an unknown corporate domain, 5 MB is safer.
How to use this tool
- Upload your PDF.
- Click Compress — targets 10 MB.
- Attach the downloaded PDF to your email.
Frequently asked questions
Why does the tool target 10 MB instead of 25 MB?
Base64 encoding adds ~33% overhead in transit. A 25 MB file becomes ~33 MB on the wire, exceeding server limits. 10 MB gives safe clearance on every provider.
My company email bounces anything over 5 MB — can I set a custom target?
Use our main Compress PDF tool and set a custom quality level, or use Compress PDF to 5 MB for a tighter target.
Will the text in my PDF still be selectable?
Pages are rasterised to JPEG for compression — text becomes an image. Use Compress PDF (quality slider) at 85%+ if you need selectable text preserved.
Can I compress a multi-attachment email PDF?
Yes. Each PDF in your email should be compressed separately. If you're attaching 3 PDFs, compress each and check their combined size fits the limit.
Is anything uploaded to your server?
No. The compression runs in your browser — your PDF stays on your device the entire time.