15sec
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A/B test your YouTube hooks before you publish.

The first 15 seconds decide whether viewers keep watching. Split your audience between alternate hooks and see which one drives the strongest retention on YouTube.

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No credit card required.

Beyond YouTube A/B testing

YouTube tests the packaging. 15sec tests the hook.

YouTube A/B testingTitle + thumbnail

Test different titles and thumbnails.

15secHook

Test alternate openings and hook edits.

How it works

Find the highest retention hook.

15sec creates an A/B test from your alternate hooks.

Learn more
  1. 01

    Upload your video and hooks

    15sec combines each hook with your finished video.

  2. 02

    Share one link

    Viewers watch your full video on YouTube with one of your hooks.

  3. 03

    Choose the winning hook

    15sec shows which hook kept the most viewers watching.

Fits your workflow

Build the test inside YouTube Studio.

The 15sec extension adds hook testing directly to your existing upload workflow.

YouTube Studio setup preview

Learnings

Every test improves the next.

15sec learns which hook patterns improve retention on your channel.

Learn more
Shock statementThe hook opens with a surprising or attention grabbing statement.
Improves retention
QuestionThe hook explicitly asks the viewer a question.
Improves retention
Curiosity gapThe hook withholds information to create curiosity.
May improve retention
MusicThe hook uses noticeable background music.
Reduces retention

Questions

Built for a private test before a public decision.

Does this publish anything to my channel?

No. Every variant stays unlisted during the test. Nothing becomes public unless you publish a version or enable automatic publishing.

Does the experiment happen inside YouTube?

Yes. Viewers watch unlisted variants on YouTube while 15sec handles assignment and comparison.

Can I test changes beyond the hook?

Yes. Test complete cuts with changes to pacing, structure, editing, or any other part of the video.

How are experiments controlled?

One link randomly assigns new viewers across concurrent variants with equal caps. Repeat viewers return to the same version.Read the experiment methodology

How do experiments get traffic?

You bring the audience. Share the test link through YouTube, Discord, email, or social media. 15sec handles the routing.

How are Learnings calculated?

Completed tests train a model for your channel. It surfaces hook patterns tied to retention and hides unstable findings.Read the Learnings methodology

You have 15 seconds to get them hooked.

Start an experiment

No credit card required.