How to Make an AI Video Longer Than 10 Seconds
Most AI video generators cap a clip at five or ten seconds because the model behind them does. Here is how scene stitching gets you to 30 or 60, what it costs, and where the real ceiling sits.
Most AI video generators stop at five or ten seconds because that is the fixed length the clip model behind them emits. HexUGC gets past that by building a video out of scenes rather than one clip: you design a reusable AI influencer once, give each scene its own still and its own line of script, and ffmpeg stitches the scenes into a single 9:16 MP4 with word-synced captions burned in. One voiced scene holds up to 60 seconds of speech, and a project holds up to ten scenes.
Why ten seconds is the usual ceiling
The limit almost never belongs to the tool you are using. Video models generate a clip of a fixed duration, and the product wrapped around one inherits that number. So the honest question is not which generator makes long videos, it is what happens after the clip comes back.
There are two answers and only one of them works: cut several takes together. That fails for a specific reason. Your character has to survive the cut, and three clips from a tool that draws a fresh face each time give you three people having one conversation.
Scenes are the unit, not clips
In the create wizard a video is an ordered list of scenes. Each scene picks a still out of your library, takes its own direction, and carries its own part of the script. The pipeline runs each scene, then composes once at the end, so what you download is one file rather than a folder you assemble yourself.
The face holds because every still traces back to the same character board: one sheet of your influencer front, left, right and back, generated at the start and reused for every shot after it. Scene four can be a different room, a different angle and a different outfit, and still be recognisably the same person.
Ten scenes is the cap per project.
The length comes from the script, not a slider
There is no duration control to set, because a talking clip's length is simply how long the words take to say. HexUGC estimates spoken length from the script at about 2.5 words a second, then charges on that estimate and caps the audio to it. Roughly 25 words is ten seconds, 75 words is thirty.
Two edges worth knowing. A single scene refuses a script longer than 60 seconds of speech and asks you to trim it. And a silent scene, one with no voiceover, snaps to five or ten seconds, because that is what the animation model emits.
What a longer video costs
Credits meter the lip-sync per second, so length is the main lever on the bill. One credit is $0.10 at the list rate, and half that on a plan.
| Video | How it is built | Credits |
|---|---|---|
| 10 seconds | one voiced scene | 28 |
| 20 seconds | one voiced scene | 48 |
| 30 seconds | one voiced scene | 68 |
| 30 seconds | three 10-second scenes | 82 |
The last two rows are the pair worth reading. Cutting the same thirty seconds into three scenes costs about fourteen credits more, because each scene gets its own still and its own voiceover pass. At the ten-second size, Starter at $15 a month works out at roughly 10 videos and Creator at $30 at roughly 21.
How long the video should actually be
The ceiling is not the target. Most short-form that holds attention runs fifteen to thirty seconds, carries one idea, and cuts every five to eight seconds so the frame keeps changing. Reaching for sixty because you can is usually a retention problem you have chosen on purpose.
A useful default: write the script first at the length the idea needs, then split it where the thought changes. Those splits are your scenes. If you want the full sequence from character to finished file, we wrote up the whole workflow separately.
What this does not do
This is short-form machinery, not a long-form tool. Ten scenes of sixty seconds is a hard ceiling, and nothing near it belongs in a feed.
Scenes are cuts, not one continuous take. Each is generated on its own, so the camera does not track across a boundary and a gesture does not carry over. Write to the cut rather than fighting it.
Longer videos take longer to make. Lip-sync dominates the run and scales with clip length, though scenes inside one project generate in parallel, so a three-scene video is roughly the slowest scene plus the stitch rather than three runs end to end. We measured the real timings on a single video.
Batch generation, several variants from one action, is on our roadmap rather than shipped, so each video is its own run. There is no publishing or scheduling either: you download the MP4 and upload it yourself.
Where to start
Write thirty seconds of script, split it into three scenes, and see whether the cuts hold before spending anything on a longer one.