There is no single right answer, which is why the question keeps getting asked. Length depends on where the video runs and what it is meant to do, and getting it wrong in either direction costs you.
The working numbers
- Vertical social — 15 to 30 seconds. Long enough to make one point, short enough to be watched twice. Past about 45 seconds completion falls off a cliff on every platform.
- Paid social — 15 seconds. You are interrupting somebody. Say the thing.
- Property or product walkthrough — 60 to 90 seconds. Enough to understand a layout or a machine, not enough to lose the thread.
- Website hero loop — 8 to 12 seconds, silent, looping. Nobody watches this deliberately; it is texture.
- Testimonial — 45 to 75 seconds. Beyond that it stops sounding like a person and starts sounding like a script.
- Long-form explainer — as long as it earns. Somebody searching for how a process works will watch six minutes. Somebody scrolling will not watch six seconds.
The first three seconds matter more than the length
Every platform decides how far to push a video based on early retention. If people drop in the first three seconds, total runtime is irrelevant because nobody reached it. A 20-second video with a weak opening performs worse than a 90-second one that starts with the finished driveway, the boat at speed, or the machine already working.
Open on the outcome, not on your logo. An intro card is three seconds of the only attention you are guaranteed, spent on something the viewer did not ask for.
Cut for the platform, not once for everything
The most common mistake is producing one video at one length and posting it everywhere. The same shoot should produce a 15-second vertical cut, a 60-second walkthrough and a handful of stills — that is a planning decision made before anyone arrives, not an editing decision made afterwards.
More on getting several deliverables out of one day in what actually happens on a content shoot day.
When longer genuinely wins
High-ticket, considered purchases reverse the usual advice. Somebody deciding on a yacht or a piece of plant will watch a full walkthrough, and cutting it short to chase a retention metric removes the detail they came for. The audience is small and already interested; the job is to satisfy them, not to reach more people.
There is more on that in does short-form video work for high-ticket sales.
A test worth running
Take your best-performing piece and cut a version half the length, opening on the strongest three seconds. Run both. In most accounts the shorter one wins, and the margin tells you how much your openings have been costing you.