AI video makers for social: loops, captions and motion

An AI video maker for social media needs to do three things well: produce vertical video at the right size, keep captions readable on a phone and loop cleanly when the platform replays it. Different tools get there in different ways. Some generate footage from a prompt, some put a talking presenter on screen, and some animate a design you already have. For announcements, quotes, offers and tips, an animated design is usually the fastest route to something that looks like your brand.

Three kinds of AI video maker

Many social videos are really moving graphics: words on a background, a logo, a short message. A motion design tool gives you control over exactly those parts, and the result stays on brand because it starts from your own layout. Animated social posts has ideas for this kind of video.

Sizes for social video

Vertical video fills a phone screen and is the default on Stories, Reels, TikTok and Shorts. Feed posts still accept portrait and wide video, so make the vertical version first and adapt it. The full list is in social video sizes.

Captions people can actually read

Many people watch with the sound off, so on-screen words carry the message. AI can transcribe speech into captions quickly, but placement and size are still your job. In a vertical frame, the platform's own interface sits across the bottom and down the right side. Captions placed there get covered.

Video captions design goes into type, timing and safe zones. If you are using a background that moves, readability can change from second to second, which is where a background that responds to the words helps.

How to make a seamless loop

A seamless loop is a short video whose last frame flows straight back into its first. Platforms replay short videos automatically, so a clean loop looks intentional while a hard cut back to the start looks like a mistake. Loops also suit still words: the background drifts, the message stays put.

1. 1

   Keep the words still

   Let text arrive once, then hold. Moving words are harder to read and harder to loop.

2. 2

   Move the background slowly

   Gentle drift reads as calm and premium. Fast motion competes with the message.

3. 3

   Match the first and last frames

   Motion that returns to where it started joins invisibly. Check the join by watching it replay three times.

4. 4

   Choose a sensible length

   Long enough to read the words twice, short enough that it replays before attention drifts. Video loop length has guidance per platform.

5. 5

   Export at the platform size

   MP4 at 1080×1920 for vertical. Upload the file as made, so the app has nothing to rescale.

There is more on the technique, including how to test the join, in seamless loop video.

Making social video in Gradiently

Gradiently is a design tool built around Marks, living gradient and material backgrounds with their own light, grain and motion. Text can animate in with a rise, pop, wipe or typewriter, and the Mark keeps its calmest region behind the words so captions stay readable while it moves. On Pro you get a video timeline with captions, music, camera, screen and voice recording, and export as MP4, WebM or GIF where the browser supports recording, up to 4K with no watermark.

The Designer, Gradiently's AI, can lay out a post on your Mark from a sentence and make the other sizes, so the vertical loop and the feed version come from one design. For recording yourself, see record screen in browser.