What is the best video length for ads?
As short as the message allows, within what the platform recommends. For most feed ads that means under 30 seconds, and often much shorter.
The reason is simple. In a feed, nobody chose to watch your ad. Each second has to earn the next, and the message has to land even for people who only see the start. Longer ads can work, but only when the extra time adds something the viewer wants.
What does each platform recommend?
Here's what each platform says in its own guidance. Check the current advice before you brief, because platforms update it.
- Meta (Facebook and Instagram): keep it short, with 15 seconds or less recommended, and get the brand and message in early. Vertical works best for Reels and Stories.
- TikTok: 21 to 34 seconds is the recommended length for in-feed ads, with the hook in the first 3 seconds. It should feel like a TikTok, not a TV ad.
- YouTube and Google: bumper ads are up to 6 seconds and can't be skipped. Skippable in-stream ads can be skipped after 5 seconds, so those first seconds carry the message. Non-skippable in-stream ads are 15 seconds or shorter on most placements.
- LinkedIn: video ads can run from 3 seconds to 30 minutes, but LinkedIn recommends shorter videos for awareness and longer ones only where the content earns it.
Why do short video ads usually win in feeds?
Because people are scrolling, not settling in. A short ad gets its point across before attention drifts, and it's more likely to be watched to the end.
Short ads are also cheaper to make in volume. That matters, because you'll want several hooks and versions to test, and fresh ones when the old ones tire.
When does a longer video ad work?
A longer ad works when the viewer already cares, or when the product needs explaining. These are the usual cases.
- Retargeting people who've visited your site and want more detail.
- Products that need a demo, such as software or equipment.
- Customer stories and testimonials, where the detail is the proof.
- YouTube, where people who don't skip have chosen to keep watching.
- B2B audiences on LinkedIn, researching a bigger decision.
How do you choose the right length for your ad?
Work through these steps for each campaign. They take the guesswork out of it.
- Pick the platform and placement first. A Reel, a YouTube pre-roll and a LinkedIn feed ad are different jobs.
- Check that platform's current length guidance and limits.
- Write the one thing the viewer must take away, in a single sentence.
- Count how many seconds that message really needs, with the hook in the first few.
- Edit the longest version that's still tight, then cut it down to shorter versions.
- Run the versions against each other with the platform's own testing tools, and keep the winner.
How do you make one video work at several lengths?
Plan the cut-downs before you film. Build the ad in blocks: hook, problem, proof, offer, call to action. Then each shorter version keeps the hook and the offer and drops a block from the middle.
A common set is a 6-second version for bumpers and quick reminders, a 15-second version for feeds and Stories, and a 30-second version for TikTok, YouTube and retargeting. Export each in the sizes the placement needs, such as 9:16 and 4:5.
Does the hook matter more than the length?
Usually, yes. A 30-second ad with a strong opening beats a 10-second ad with a weak one. Length decides how much you can say. The hook decides whether anyone hears it.
Open on the result, the problem or the most surprising line. Put the brand early, add captions so it works on mute, and make the call to action clear before the end.