Why a 24 MB video still bounces
Email can only carry text, so attachments are converted to text (base64) when sent — and that makes them about 33% bigger. A 24 MB video becomes a 32 MB message and is rejected by a 25 MB limit. Safe file sizes are:
- Gmail, Yahoo (25 MB): up to about 18 MB
- Outlook (20 MB): up to about 14 MB — choose the Outlook preset under Advanced → Preset
Too long to fit?
18 MB holds roughly 2 minutes of 720p video. For longer recordings either lower the resolution (Resolution → 480p or Auto) or split the video into parts and send several emails. Gmail will also offer a Google Drive link for bigger files — but then the recipient needs to download it from Drive.
Several videos in one email
The limit is for the whole message. If you attach three videos, set the slider to a third of 18 MB — or compress them separately and send separate emails.
Attachment limits by email provider
| Provider | Limit per message | Safe video size |
|---|---|---|
| Gmail | 25 MB | 18 MB |
| Yahoo Mail | 25 MB | 18 MB |
| Outlook.com / Microsoft 365 | 20 MB (some business setups 10 MB) | 14 MB |
| iCloud Mail | 20 MB (Mail Drop for bigger files) | 14 MB |
| AOL, Proton (free) | 25 MB | 18 MB |
| Corporate Exchange servers | often 10 MB | 7 MB |
The “safe size” already includes the roughly one-third growth from base64 encoding, plus a little space for the text of your message and signatures.
Why not just send a Google Drive or OneDrive link?
A link is fine for long videos — Gmail does it automatically above 25 MB. But a real attachment has advantages: it plays right in the email on the recipient’s phone, it doesn’t expire or depend on sharing permissions, it works when the recipient’s company blocks cloud links, and it can be archived with the email. For a short clip — a product demo, a bug report, a video for a job application — an attachment is simply friendlier.
How long a video fits in an email?
- 18 MB at 720p: about 1 minute at good quality, 2 minutes at acceptable quality.
- 18 MB at 480p: about 3 minutes — fine for talking-head video.
- Longer videos: split into several emails with “Split into parts”, or use a link.
Make sure it plays for the recipient
This preset produces MP4 with H.264 video and AAC sound — the one combination that previews in Gmail, Outlook and Apple Mail on every device. iPhone videos in HEVC (and especially HDR) often show only as an attachment icon on Windows; after conversion they play everywhere.
Questions
What is the maximum attachment size in Gmail?
25 MB per message, but because of encoding the attached file should be about 18 MB or less.
And in Outlook?
Outlook allows 20 MB per message in most setups, so keep the video under about 14 MB.
Will the recipient be able to play it?
Yes — the default format is MP4 with H.264 video and AAC audio, which plays on every phone, computer and email app.
Why does Gmail turn my attachment into a Drive link?
Because the message would be over 25 MB after encoding. Compress the video to 18 MB and it stays a normal attachment.
What is the best format to email a video?
MP4 with H.264 video and AAC audio. It previews in every mail app and on every phone.
Last updated: 2026-10-30