Email Attachment Size Limits and How to Shrink Files
Know the limit, then shrink the file in your browser without uploading it anywhere.
Attachment limits by email service
| Email service | Attachment limit | Notes |
|---|---|---|
| Gmail | 25 MB | Larger files are shared as a Google Drive link. |
| Outlook.com / Hotmail | 20 MB | Larger files are offered through OneDrive. |
| Yahoo Mail | 25 MB | Attachments count towards the total message size. |
| iCloud Mail | 20 MB | Mail Drop can send larger files through iCloud. |
| Proton Mail | 25 MB | Total message size including attachments. |
Make your file small enough
- Compress image to 500KB
- Compress image to 1MB
- Compress PDF
- Compress video to 25MB
- Compress video to 16MB
- Send large files directly
Email attachment limits apply to the whole message, and attachments are encoded before sending, which makes them about a third bigger. A 20 MB file can therefore be rejected by a 25 MB limit. Reducing the file first is more reliable than hoping it fits.
Frequently asked questions
What is the biggest file I can email?
Most large providers allow about 20 to 25 MB per message. Email encodes attachments, which adds roughly a third, so aim for files well under the limit.
How do I make a photo small enough to email?
Use the compress-to-KB image tools. A photo of 300 to 500 KB is plenty for viewing on screen.
How do I shrink a PDF for email?
Use the compress PDF tool. It works in your browser, so private documents are not uploaded.
How do I send a video that is too big?
Use a compress-video-to-MB tool, or skip email and use the private file transfer tool to send it directly.
Are these limits exact?
They are the commonly published limits and providers change them, so check your email service's help page.
Why did my email bounce even though the file was under the limit?
The limit applies to the whole message, including encoding overhead, other attachments and the recipient's own limit.
Is it safe to compress files here?
Yes. All compression runs in your browser and nothing is uploaded.