"How long should my clip be?" has a real answer, but it's a function, not a number: length is a bet against completion rate, priced differently per platform and per moment type. Here's the decision made properly.
The math that governs everything
Algorithms reward completion, and completion is a fraction with length in the denominator. A 20-second clip watched fully signals harder than a 55-second clip watched 70% through — even though the longer clip delivered more watch time. Every second you keep must earn its place against the completion cost. That single idea replaces all the folklore.
Platform bands (as defaults, not laws)
- TikTok: 15–30s for single-moment clips; the feed is retention-ruthless. 30–45s only when the moment genuinely builds.
- Shorts: 20–45s comfortably; intent-driven viewers and the loop/rewatch dynamic tolerate a beat more setup — and a clean loop point matters more than raw length.
- Reels: 15–35s — share-framed clips skew shorter because shared clips get watched in DMs by cold viewers.
- X: under 45s for autoplay retention; the quotable line decides more than duration does.
Length by moment type (the better lens)
- One-beat comedy / fails / reactions: as short as the beat allows — 12–25s. If it fits in 15, 25 is a worse clip.
- Clutch plays: 3–5s of stakes-setting, the play, one beat of reaction. Usually 20–35s. Stakes must read visually.
- Stories with a turn: 30–60s — the one category where cutting too short kills the payoff. Trim inside the story (every um, every tangent) rather than truncating the arc (podcast rules).
- Takes/arguments: exactly as long as the complete thought, not one sentence more — end on the quotable line.
When longer wins
Longer clips justify themselves only when they re-hook mid-clip — a twist, an escalation, a second payoff that resets the viewer's attention clock. If your 50-second cut has a flat middle, it's a 28-second clip with padding. The test: watch your own cut and note the second where you'd swipe. That second is your real ending.
The practical procedure
- Cut the moment to its natural arc, ignoring length.
- Trim every second that doesn't earn its completion cost — setup first, trailing content second.
- Check the band for your target platform; if you're way over, you probably have two clips (and two clips are two bounties).
- Let your retention curves refine your personal bands — your niche's tolerance is an empirical fact, not a blog's opinion.
Short isn't the goal; dense is. Length is just where density shows up in the numbers.