An app promo has about five seconds to show the core loop, which is the one interaction the whole product exists for. Everything else, the onboarding, the settings, the clever secondary feature, is competing with that five seconds and losing. Board the loop first and then decide whether anything else earns a place.
The structure
0-2s: the outcome. What the app produces, before any interface appears. A finished thing, a saved moment, a solved problem.
2-8s: the core loop. Real screen, real interaction, at real speed. This is the video.
8-15s: one supporting capability. One. Not four.
15-20s: proof and action. Rating, count, or a recognisable name, then the store.
Under twenty seconds for social, and store previews follow the platform's own length rules rather than yours.
Screen recordings beat mockups
Record the actual app. Animated mockups of interfaces are faster to produce and read as concept work, and viewers who have seen a hundred app promos can tell the difference instantly.
Two practical rules for the recording: slow the interaction down slightly in the edit rather than performing it slowly, and keep the finger or cursor visible so the viewer knows what caused the change. Screens that change without visible cause read as video, not as software.
What store rules change about the board
App store preview requirements govern length, orientation, capture source, and whether you may show anything that is not the app. Some of them prohibit device frames or require footage captured on-device. Board against the specific store's current rules, not against a general idea of them, because a rejected preview costs a release cycle.
That constraint is why most teams end up with two videos: a compliant store preview and a freer social cut.
What to generate
Generate: the context around the screen, the environment, the lifestyle framing, the abstract before-state, and the social-cut backgrounds. Canon prices, a credit at $0.01: an 8-second Veo 3.1 Lite clip silent is 33 credits, so the surrounding tissue for a promo runs a couple of dollars.
Do not generate: the interface. Generated UI is wrong in ways your users notice immediately, and store rules generally require the preview to depict the actual app.
FAQ
How long should an app promo video be? 15 to 20 seconds for social. Store previews follow the platform's stated limits, which differ by store and change.
Should the video have narration? For social, usually not: it plays muted. Use captions and let the screen carry it. See how to caption video for silent viewing.
How many features should it show? The core loop plus one. Promos that show four features communicate none.
Show the loop, record the real screen, generate the world around it. The 8frame canvas is free and unlimited, and generation is paid from $19/month.