A guide on the formats each platform allows, what kind of processing happens to your video when it is uploaded, and the ideal size to aim for.
Every number checked against its source on 3 October 2026 · re-checked twice a month
The tables below give a breakdown of what is allowed for each platform. What it allows is the platform's own limit, in its own words. What it does to your video is what happens after it arrives, which matters more than the limit: an app that re-compresses everything to 720p throws away whatever you send above that. Aim for is what our video compressor tool targets, which comes in at slightly under each limit.
Gmail takes 25 MB of attachments, counted as the files are. Outlook.com and Yahoo take 20–25 MB a message, which may be counted after sending adds about 37%. The Outlook app takes 20 MB a message.
The one place where the limit isn't what it looks like. Attachments are encoded for transit, which makes them about 37% bigger on the way, so a 20 MB video can be counted as 27 MB and refused. And the limit that matters is the smaller of two: yours decides whether the message leaves, the recipient's whether it arrives.
| Sending from | What it allows | What it does to your video | Aim for |
|---|---|---|---|
| Gmail | Gmail takes 25 MB of attachments, counted as the files are | Arrives exactly as you sent it | 25 MB |
| Outlook.com, Yahoo or other | Outlook.com and Yahoo take 20–25 MB a message, which may be counted after sending adds about 37% | Arrives exactly as you sent it | 18 MB |
| Outlook app | The Outlook app takes 20 MB a message | Arrives exactly as you sent it | 14 MB |
| Work email | Many work accounts (Exchange) take 10 MB a message | Arrives exactly as you sent it | 7 MB |
Compress video for email picks your provider's limit and shares one email's worth between several videos.
Discord's free limit is 20 MB (since 13 Aug 2026). Nitro Basic takes 50 MB. Nitro takes 500 MB.
A Discord file arrives exactly as you sent it, so the limit is the whole story — and it went up to 20 MB for free accounts in August 2026, though some people still see 10.
| Platform | What it allows | What it does to your video | Aim for |
|---|---|---|---|
| Free | Discord's free limit is 20 MB (since 13 Aug 2026) | Arrives exactly as you sent it | 19 MB |
| Nitro Basic | Nitro Basic takes 50 MB | Arrives exactly as you sent it | 47 MB |
| Nitro | Nitro takes 500 MB | Arrives exactly as you sent it | 475 MB |
To get under it, compress the video for Discord: pick Discord and the size is set for you. For a short loop, make a GIF instead.
WhatsApp re-compresses videos to 480p, or 720p in HD; its 16 MB limit is widely quoted but not published. Telegram takes 2 GB (4 GB with Premium).
Messaging apps re-compress whatever you send, usually to about 720p. Sending a 4K original wastes the wait and gains nothing: a clean 720p arrives looking the same or better.
| Platform | What it allows | What it does to your video | Aim for |
|---|---|---|---|
| WhatsApp * | WhatsApp re-compresses videos to 480p, or 720p in HD; its 16 MB limit is widely quoted but not published | Re-compressed, about 720p, 30 fps at most | 15 MB |
| iMessage * | About 100 MB (Apple doesn't publish it) | Re-encoded, 1080p at most, 30 fps at most | 95 MB |
| Signal * | Signal takes 200 MB (since 31 Jul 2026) | Re-compressed, about 720p, 30 fps at most | 190 MB |
| Messenger | Messenger takes 100 MB (since April 2025) | Re-compressed, about 720p, 30 fps at most | 95 MB |
| Telegram | Telegram takes 2 GB (4 GB with Premium) | Re-encoded, 1080p at most | 1.9 GB |
Compress video has a setting for WhatsApp and the other messaging apps that sends a clean 720p.
Instagram Reels take 300 MB, 15 minutes and 1920 pixels wide. TikTok takes 4 GB, 4096 pixels a side and 23–60 fps. X takes 512 MB and 2 min 20 s on a free account (16 GB with Premium).
Social platforms take large files and then re-encode hard. The aim is to hand them a good 1080p source rather than the biggest file they'll accept.
| Platform | What it allows | What it does to your video | Aim for |
|---|---|---|---|
| Instagram Reels take 300 MB, 15 minutes and 1920 pixels wide | Re-encoded, 1080p at most, 60 fps at most | 285 MB | |
| TikTok | TikTok takes 4 GB, 4096 pixels a side and 23–60 fps | Re-encoded, 1080p at most, 60 fps at most | Its own size |
| Facebook Reels have no length or format restrictions (since June 2025) | Re-encoded, 1080p at most, 60 fps at most | Its own size | |
| X | X takes 512 MB and 2 min 20 s on a free account (16 GB with Premium) | Re-encoded, 1080p at most, 60 fps at most | 480 MB |
| LinkedIn takes 5 GB and 15 minutes | Re-encoded, 1080p at most, 60 fps at most | Its own size | |
| Snapchat * | Snapchat doesn't publish its limits | Re-encoded, 1080p at most, 60 fps at most | Its own size |
| Threads | Threads takes 1 GB and 5 minutes | Re-encoded, 1080p at most, 60 fps at most | 950 MB |
| Bluesky * | Bluesky takes 300 MB and 10 minutes (since 25 Aug 2026) | Re-compressed, about 720p | 285 MB |
For Reels, TikTok and Stories, crop the video to 9:16 (or 4:5 for Instagram's feed), then compress it for the platform.
YouTube gives better streams to bigger, sharper videos, so the picture keeps its size. Shorts are up to 3 minutes, vertical or square.
Video hosts are the exception: they give better streams to bigger, sharper uploads, so the picture keeps its size. Compressing only makes the upload quicker.
| Platform | What it allows | What it does to your video | Aim for |
|---|---|---|---|
| YouTube | YouTube gives better streams to bigger, sharper videos, so the picture keeps its size | Arrives exactly as you sent it | Its own size |
| Shorts | Shorts are up to 3 minutes, vertical or square | Re-encoded, 1080p at most | Its own size |
| Vimeo | Vimeo re-compresses everything; bigger, sharper videos stream better | Arrives exactly as you sent it | Its own size |
To fit Shorts' 3 minutes, trim the video to the exact frame, with nothing re-encoded. Most hosts take MOV files; if one doesn't, convert the MOV to MP4.
* Not published by the platform: the figure is the best reported one, and we keep further under it.
Get your video to the right size Compress video
Email attachments are encoded as text to be sent, which makes them roughly 37% bigger in transit. Some providers measure the encoded size, so a 20 MB video can be counted as about 27 MB. Gmail is the exception: it counts the files as they are, so its 25 MB is 25 MB of video.
Yes. WhatsApp re-compresses what you send, to about 480p normally or 720p with HD on. Sending a 4K original doesn't survive that, so a clean 720p at 30 frames a second arrives looking the same and sends in a fraction of the time.
Instagram Reels accept up to 300 MB, 15 minutes and 1920 pixels wide, and Instagram re-encodes everything it's sent, so a good 1080p source is the target rather than the largest file it will take.
For YouTube and Vimeo, roughly yes: they re-encode everything and give better streams to sharper, higher-bitrate sources, so keep the picture at its own size. For messaging and social apps, no: they cap what they show, so anything above that cap is thrown away.
Often. Discord's free limit doubled in August 2026, Signal's went to 200 MB in July 2026, and Bluesky's changed the same month. Every number here says when it was last checked, and they're re-checked twice a month.
Compress it in your browser with Oh So Video. Pick where it's going and the size is set for you, the result is never over the limit, and your video never leaves your device: there's nothing to upload and no account.