"Keep it short."
It's the most repeated advice in social media and it's mostly wrong.
We pulled the duration and engagement data on 8,000+ videos across TikTok and Instagram Reels. What we found doesn't match the conventional wisdom.
Here's what the actual data says.
The short answer: 60 to 90 seconds
On both TikTok and Instagram Reels, videos in the 60 to 90 second range outperform everything else in average views and engagement rate. Not 15 seconds. Not 30 seconds. 60 to 90.
60-90s
Optimal length
368K
Avg TikTok views
457K
Avg Reels views
8.8%
TikTok engagement
Now let's break down exactly what the data shows and why most "experts" have been telling you the wrong thing.
TikTok video length vs engagement
TikTok Average Engagement Rate by Video Length
Engagement actually drops between 15 and 60 seconds. It hits a low at 45-60 seconds (6.3%) before jumping back up to 8.8% once videos cross the 60-second mark.
The 0-15 second range pulls decent engagement (7.9%) because super-short videos rely on loops and rewatches to inflate metrics. But they don't hold attention long enough to drive real engagement actions like comments and shares.
The real engagement happens when you have enough time to actually say something.
TikTok video length vs average views
TikTok Average Views by Video Length (in thousands)
This chart is where the advice really falls apart.
Videos in the 0-15 second range average only 53,000 views. That's the worst performing category. The "keep it under 15 seconds" advice is based on something that simply isn't true in the current algorithm.
60-90 second videos average 368,000 views. That's nearly 7x more than 15-second videos.
The 3+ minute category averages 612K views, but that's a small sample of 24 videos and mostly bigger creators. If you're starting out, aim for 60-90.
TikTok's algorithm now rewards longer watch times more than short clips. A 90-second video that holds someone's attention generates more algorithmic signal than a 15-second video that loops 5 times.
Instagram Reels tell a different story
Instagram Reels Average Views by Video Length (in thousands)
Instagram Reels actually does favor shorter videos for raw views. 0-30 second Reels pull around 700K average views, which drops as videos get longer.
But here's the twist. When you look at engagement rate on Reels:
Instagram Reels Engagement Rate by Length
Engagement on Reels climbs steadily as videos get longer, peaking at 60-120 seconds with 4.7-4.8% engagement rate. That's more than double the 2.1% engagement rate of 15-second Reels.
The trade-off: views vs engagement
Here's what the combined data actually means for your strategy:
Short videos (15-30 sec)
Best for: Raw view counts, reach, and discoverability on Instagram Reels.
Worst for: Actual engagement, comments, and audience building. Viewers scroll through them without processing.
Medium videos (60-90 sec) — THE SWEET SPOT
Best for: Engagement rate on both platforms. Strong view counts. Builds connection with your audience. Tells a complete story or takes enough to land.
Worst for: Nothing. This is the optimal range.
Long videos (2+ min)
Best for: Deep storytelling, tutorials, and case studies when you have an established audience.
Worst for: Cold reach. You need viewers who already trust you to stick around for 2+ minutes.
Why "keep it short" stopped working
Three years ago, "keep TikToks under 15 seconds" was the standard advice. Here's why that changed.
The algorithm shifted to reward watch time. Both TikTok and Instagram now optimize for total seconds watched, not number of plays. A 15-second video that gets 100 plays is worth less than a 90-second video that gets 50 plays because the second one generates more watch time signal.
Creators got better at keeping attention. The "hook first, deliver value, loop back" structure works better in 60-90 seconds than in 15 because you have time to actually set up a payoff.
Short-form burnout is real. Viewers have been scrolling 15-second videos for years. A slightly longer video that has substance is more valuable now than another 10-second clip.
What to do with this
Target 60-90 seconds as your default video length. It's the sweet spot on both platforms.
Don't artificially stretch content to fit. If the video is done at 35 seconds, leave it.
On Instagram Reels, test 15-30 second Reels for reach and 60-90 second Reels for engagement. Mix both.
If you're doing storytelling or breakdowns, 90-120 seconds is fine. Don't force it shorter.
Stop using the 'keep it under 15 seconds' advice. It's outdated.
Watch time matters more than play count. Optimize for retention, not video length.
The right TikTok length isn't 15 seconds. It's as long as it needs to be to keep someone watching and make them do something when it ends.
For most creators, that's 60 to 90 seconds.