A GIF that's too big doesn't just load slowly — most platforms reject it outright, or quietly turn it into a video. The limits differ a lot from one platform to the next, and several of them changed recently, so this guide lists only figures we checked in October 2026, plus what our own tests show about how big a GIF actually gets.
Upload limits, platform by platform
| Where | Limit for a GIF | Notes |
|---|---|---|
| Discord (free account) | 20 MB per file | Raised from 10 MB on 14 August 2026. Nitro Basic: 50 MB, Nitro: 500 MB. |
| Discord custom emoji | 256 KB | Applies to animated GIF emoji too — this is the hard one. |
| Slack custom emoji | 128 KB | Square, about 128 × 128 px. Normal GIFs in messages can be much larger. |
| X (Twitter) | 15 MB | The long-standing limit for GIFs uploaded on the web. If the mobile app refuses a GIF, upload it from the website or keep it under 5 MB. |
| GIPHY upload | 100 MB | Short clips work best; GIPHY serves them to other apps in smaller versions. |
| keep it under 1 MB | Not a hard limit, but large GIFs slow down every inbox. Outlook for Windows shows only the first frame, so make that frame work on its own. |
Older guides (and some help pages) still say Discord allows 8 MB or 10 MB — both are out of date for free accounts.
How big will your GIF be?
GIF is a very old format: it stores every frame as a separate picture with at most 256 colours. That's why a few seconds of video become several megabytes. From our own tests, converting ordinary video at 480 px wide and 12 frames per second:
- 5 seconds → about 2–4.5 MB
- 10 seconds → about 6–9 MB
Busy footage (moving camera, grass, water) sits at the top of those ranges; screen recordings and simple animations at the bottom. So a 5-second clip fits Discord and X comfortably, while an emoji has to be tiny — think 2 seconds, 128 px, few colours.
Three levers, in order of impact
- Length. Halving the duration halves the size. Cut the GIF to the moment that matters with Trim GIF — 2 to 4 seconds is the sweet spot for reactions.
- Width. File size grows with the area of the picture, so halving the width roughly quarters the size. 480 px is plenty for chat; 320 px or less for reactions; 128 px for emoji. Use Resize GIF.
- Colours and frame rate. Compress GIF reduces the palette and size in one go: in our test the Medium level took a 4.4 MB GIF to 2.5 MB (−43%) without changing its timing.
Recipes
Discord or X reaction GIF (under 5 MB): Video to GIF with a 3–4 second clip at 480 px → done. If it's still too big, Compress GIF on Medium.
Discord emoji (under 256 KB): a 1–2 second clip, Resize to 128 px wide, Crop to 1:1, then Compress on Strong. If it's still over, shorten it further — duration is usually the culprit.
Slack emoji (under 128 KB): the same as the Discord emoji, but aim for about 1 second, or a simple animation with few frames.
Email header: 600 px wide at most, 2–3 seconds, Compress on Medium, and check the first frame looks right on its own.
When a GIF is the wrong format
If what you have is longer than about 10 seconds, or full of detail, no amount of compression will make a small GIF — the format simply isn't efficient. Most places that accept GIFs also accept a short MP4 that loops: our GIF to MP4 test turned a 4.4 MB GIF into a 342 KB video (−92%) that looks better, with full colour. Keep GIF for emoji, email and places that don't accept video.