The table
Limits change; these were checked against current help pages and recent surveys in September 2026. Where a service treats media and documents differently, both are given.
| Service | Limit | Notes |
|---|---|---|
| Gmail | 25 MB per message | Larger attachments are auto-converted to a Drive link. Receiving limit is 50 MB. |
| Outlook.com | 20 MB | Microsoft 365 business accounts: 33 MB default, admin-adjustable up to 150 MB. |
| Yahoo Mail | 25 MB | |
| iCloud Mail | 20 MB | Mail Drop hands off larger files (up to 5 GB) as a link. |
| 16 MB as media · 2 GB as document | Media (photo/video from the gallery) is re-compressed to ~720p. Sending the same video through the Document picker skips compression and allows up to 2 GB, but the recipient gets a file, not an inline player. | |
| Telegram | 2 GB · 4 GB with Premium | Videos sent as media are also re-encoded; “send without compression” keeps the original. |
| Signal | 100 MB | |
| iMessage | 100 MB | Over that, iOS offers to send a lower-quality version. |
| Facebook Messenger | 25 MB | |
| Discord | 25 MB · 500 MB with Nitro | Applies per file; the free limit has changed three times since 2023. |
| Slack | 1 GB | Free workspaces may be capped lower by the 90-day history rule rather than by size. |
| ~1 GB as file | Videos sent from the gallery are re-compressed; the exact media limit is not published and has risen several times (100 MB → 200 MB → 1 GB for files). Send as file for the original. | |
| X / Twitter | 512 MB video, 140 s | |
| 4 GB video | Reels/feed are re-encoded on upload regardless. | |
| TikTok | 287 MB (web) | |
| Job portals, government forms | typically 2–10 MB per file | Set by the form, not the platform; read the field’s hint text. |
Media vs document — the distinction that matters
Every messaging app has two paths for a video. The media path (choose from gallery) is designed for phones on mobile data: the app re-encodes the file to a fixed resolution and bitrate before sending, which is why a 200 MB clip arrives as 8 MB looking slightly soft. The limit on that path (16 MB for WhatsApp) is applied before the app’s own compression, so it is the original that has to fit.
The document or file path sends bytes unchanged. Limits are far higher (2 GB), quality is preserved, but the recipient sees a file to download instead of a thumbnail that plays. For anything you care about — a wedding clip, a screen recording of a bug — send as a file. For a 20-second clip of the dog, media is fine.
Which number to aim for
When you compress to fit, aim under the limit with margin, because the limit is checked against the file as the service sees it, and metadata, container overhead and rounding all push the number up:
- E-mail: target 20 MB for a 25 MB limit. Base64 encoding of attachments adds a third — a 19 MB file becomes a 25.3 MB message and bounces.
- WhatsApp media: target 14 MB.
- Forms with a 2 MB limit: target 1.8 MB.
Making the thing fit
- PDF: compress re-encodes the images inside; that is where the weight is. A 25 MB scan usually lands at 3–5 MB at 150 dpi.
- Photos: compress at quality 80 and, if the form only needs a readable copy, resize to 2000 px on the long edge. Phone photos are 12–48 megapixels; no form needs that.
- Video: the two cheap moves that need no re-encoding are trimming to the part that matters and removing the audio if it is a screen recording. Re-encoding to a target size is what a video compressor is for; for that, freecompress.video does it in the browser with the size shown before you start.
When the limit is on the receiving end
A file that leaves your outbox fine can still bounce from the recipient’s server — corporate mail gateways commonly cap at 10 MB, and some at 5 MB. If a 20 MB attachment to a company address comes back with a “message size exceeds” error, the sending limit was never the problem; either compress to under 10 MB or use a link.