mimicVideo file
| Spec | Value |
|---|---|
| Recommended sizes | 720x1280 portrait, 1280x720 landscape, 720x720 square[2] |
| Aspect ratio | Between 1:3 and 3:1[2]16:9 (either way) and 1:1 recommended |
| Video codec | H.264 High Profile, YUV 4:2:0[2] |
| Audio codec | AAC LC, 128 kbps minimum suggested[2] |
| Frame rate | 30 or 60 fps recommended; 60 fps max[2] |
| Video bitrate | 5,000 kbps minimum suggested[2]a recommendation, not a hard limit |
| Max file size | 8 GB default, 16 GB with Premium[1]per X's API docs |
Length
Text and captions
| Spec | Value |
|---|---|
| Post text | 280 characters[3]every link counts as 23 characters |
Ads
Safe zone
| Spec | Value |
|---|---|
| Safe zone | Not published |
What X (Twitter) doesn't publish
Creators ask about these, but there's no official number. We leave them out rather than guess.
- Safe-zone margins for text
- In-app upload limits from X's Help Center (help.x.com blocked our fetch, so only the developer-docs limits are listed)
- A vertical 9:16 ratio for ad video cards (the Ads API lists 16:9 and 1:1)
Exporting for X (Twitter)
Export 720x1280 or larger
X recommends 720x1280 for portrait. Use H.264 High Profile with AAC LC audio.
Pick 30 or 60 fps
Those are X's recommended frame rates, and 60 fps is the ceiling.
Don't starve the bitrate
X suggests at least 5,000 kbps for video and 128 kbps for audio.
Make a square cut for ads
Website and app video cards take 16:9 and 1:1, so keep key text inside the centre square of a vertical edit.
Mimic exports vertical 9:16 video with captions and titles kept inside the apps' safe zones and off the speaker's face.
Sources
- [1] X Developer Platform, Media upload endpoints on the X API v2. Checked October 2026.
- [2] X Developer Platform, Media best practices. Checked October 2026.
- [3] X Developer Platform, Counting characters. Checked October 2026.
- [4] X Developer Platform, Creatives (X Ads API). Checked October 2026.
Platforms change limits without notice. Check the linked page before a big campaign.
Questions
How long can a video on X be?
X's API docs list 20 minutes for regular accounts and 125 minutes for Premium or verified accounts, with a 0.5-second minimum.
What resolution should X videos be?
X recommends 720x1280 for portrait, 1280x720 for landscape and 720x720 for square.
What is the maximum video file size on X?
8 GB by default and 16 GB for Premium, per X's API docs. Promoted videos are capped at 500 MB.
How many characters can an X post have?
280, with every link counted as 23 characters.
Made for X (Twitter), edited by Mimic.
Raw clip in. Captions, cuts, hook and product shots out.
Get started