Can I Email This File?
Drop in a file to check it against Gmail, Outlook, iCloud, Yahoo, and Slack attachment limits — including the base64 encoding overhead most tools ignore. Free, nothing uploaded, no signup.
Drop your files here
Nothing is uploaded — the check runs entirely in your browser.
Email attachment size limits (2026)
| Service | Send limit |
|---|---|
| Gmail | 25 MB |
| Outlook / Microsoft 365 | 20 MB (Outlook.com) |
| Yahoo Mail | 25 MB |
| iCloud Mail | 20 MB (5 GB via Mail Drop) |
| Proton Mail | 25 MB |
Limits apply to the whole message, and the encoded payload is about 37% larger than the raw file. When in doubt, keep total attachments under ~15 MB or send a link.
Questions, answered.
- What is the maximum email attachment size?
- Most email providers cap attachments at 20–25 MB per message: Gmail and Yahoo allow 25 MB, while Outlook.com and iCloud Mail allow 20 MB. Because email encodes attachments as base64 text, the real payload is about 37% larger than the file on your disk, so a 20 MB file can already exceed a 25 MB limit.
- Why does my file get rejected even though it's under the limit?
- Email attaches files using base64 encoding, which inflates the size by roughly a third. A 19 MB file becomes about 26 MB in transit, which is why it can bounce against a 25 MB cap. This checker compares the encoded size — not the raw size — so it reflects what the provider actually measures.
- Does zipping a file make it small enough to email?
- Usually not. Photos, videos, PDFs, and most design exports are already compressed, so a ZIP barely shrinks them. Zipping is useful for bundling many files into one attachment, but for large media the reliable fix is to send a download link instead of an attachment.
- Is anything uploaded when I use this tool?
- No. The checker only reads each file's name and size in your browser to compare against provider limits. The file contents never leave your device and nothing is sent to a server.
- How do I send a file that's too big to email?
- Share a download link instead of attaching the file. For client work, FileDue creates a single link that stays locked until the client pays, so you deliver large files and get paid at the same time — with no attachment size limit.
Too big to email? FileDue gives you one link that stays locked until the client pays — no attachment size limit, and no chasing the invoice afterward.
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