How to Choose AI Video Length
Plan in shots and usable seconds; verify the choices your model actually offers.
Step by step
Define one viewer action
Decide what the viewer should notice or do. A single product reveal needs less time than a demonstration with several claims.
Break the idea into shots
Write one subject action and one camera move per shot. Complex multi-action prompts are harder to keep coherent.
Check current generator choices
Duration options and credit cost can vary by route, model and plan. Use the signed-in controls as the source of truth.
Generate the minimum useful shot
Shorter test shots can reduce the cost of a failed concept, but only when the chosen model actually offers them.
Edit for the destination
Combine accepted shots, captions and audio in an editor, then check the current publishing limits of the destination platform.
Pro tips for better results
- Count usable seconds, not generated seconds.
- Do not infer retention from duration alone.
- Keep failed and discarded generations in cost calculations.
- Platform maximums are not recommendations.
Generated shot versus final edit
A 30-second ad may consist of six accepted shots, titles and a call to action. Judge the generator on shot continuity and usable yield; judge the final edit on clarity and audience response.
A simple planning equation
Planned final length = accepted shot seconds + titles/transitions. Production cost should include all attempted shots, including blocked, failed and discarded generations.
Original duration-coherence protocol (not executed)
Test input: A paper boat travels from left to right through a shallow rain puddle, locked low camera, overcast daylight, no cuts, no text.
Settings: Run the same prompt at every duration currently offered by the selected model.
- Usable seconds
- Direction continuity
- Shape drift
- Credit cost per accepted second
Status: This separate protocol was not executed. The visible executed sample below uses a different disclosed input and must not be treated as its result.
Requested duration versus usable framing
Actual application handler, isolated environment, real provider; not the production browser/UI.
Prompt: A gentle slow camera push toward the orange mug. Keep the mug shape and handle stable. No new objects.
Recorded settings: Requested 4 seconds at 720p; ffprobe measured exactly 4.000 seconds.
Observed result and limitations: Duration matched this one request, but initial black side areas and later circle cropping show that generated seconds are not automatically usable seconds.
Why it matters here: Only the four-second case was executed; it says nothing about other durations, consistency or extensions.
This is one of the same three image edits and one video reused across these 12 pages. It is a small illustrative sample and cannot be generalized. Read the evidence manifest.