Email attachment size limits by provider
Even if your email provider allows 25MB, corporate mail gateways and antivirus filters at the recipient's end often block large attachments. Keeping PDFs under 5MB ensures delivery everywhere, including to government and bank email servers which have stricter limits.
| Email Provider | Attachment Limit | Safe Target |
|---|---|---|
| Gmail | 25MB per email | < 10MB recommended |
| Outlook / Hotmail | 20MB per email | < 10MB recommended |
| Yahoo Mail | 25MB per email | < 10MB recommended |
| Corporate mail (govt, banks) | 5–10MB typical | < 5MB to be safe |
| Rediffmail | 10MB per email | < 5MB recommended |
| WhatsApp (doc) | 100MB per file | < 16MB for fast delivery |
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How to compress your PDF for email (3 steps)
Upload your PDF using Choose PDF or drag and drop. Presentations, reports, brochures, certificates — any PDF works.
The target is pre-set to 5MB — the sweet spot for guaranteed delivery across all email providers. Click Compress PDF for Email.
Download the compressed PDF and attach it to your email normally. No special steps needed — the file opens on all PDF viewers at the other end.
Frequently asked questions
Why do large PDF emails bounce even under the limit?
Email size limits apply to the total message size, not just the attachment. Email attachments are base64-encoded, which adds ~33% to the file size in transit. A 20MB PDF becomes ~27MB in the email, pushing it over Gmail's 25MB limit. Compressing to 5MB gives you plenty of headroom.
Should I use WeTransfer instead of emailing large PDFs?
For PDFs over 10MB, sharing via Google Drive, OneDrive, or WeTransfer is more reliable than email attachments. The recipient gets a download link instead. This tool is best for compressing to email-friendly sizes when you specifically need an attachment (for job applications, government forms, etc.).
Can I set a custom size like 3MB instead of 5MB?
Yes — after the tool loads, switch to Target Size mode and type your exact target. The tool will auto-compress to any size you specify.