How long should an ad video be on each platform
Every platform publishes a maximum and a recommendation, and they're nowhere near each other. Two also have thresholds that break your funnel.
Maximums are ceilings, not targets, and treating them as targets is how you end up with a two-minute ad nobody finishes. Here's what each platform actually publishes.
| Platform | Recommended | Maximum |
|---|---|---|
| TikTok | Not stated on the in-feed page | Up to 10 minutes |
| 6 to 15 seconds | 15 minutes, minimum 4 seconds | |
| X | 15 seconds or less | 2 minutes 20 seconds |
| YouTube | 15 to 20s for awareness, 2 to 3 min for consideration | Varies by format |
Two YouTube thresholds that aren't about attention
Google states that view counts aren't incremented below 10 seconds, and that remarketing lists and YouTube Analytics need 12+ seconds. These aren't performance guidance. They decide whether you get any data at all, so a 6-second bumper builds no audience for whatever you planned to run next.
The first five seconds are the only ones you're guaranteed
A skippable in-stream ad can be skipped after 5 seconds. Whatever the total length, everything the ad must communicate has to survive being abandoned at five. X reaches a similar conclusion from a different direction: it advises 6 to 15 second videos with captions and prominent branding.
File size is a separate trap
X allows 1GB and then says to keep files under 30MB for performance. Pinterest allows 2GB. Those aren't invitations. Upload the ceiling and you'll watch delivery suffer for a reason that never appears in any report.