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Ad testing with facial coding
EchoDepth pre-tests video ads on real people. A sample of viewers matched to your audience, 15 or more per audience segment, watches your ad at home on their own webcam, after giving consent. We code their facial response on every frame against 44 Action Units from the Facial Action Coding System, convert it into valence, arousal and dominance, and plot it as the Emotional Response Curve. What viewers say afterwards is scored as the Cavefish Emotional Index. You see where the ad builds enjoyment, where it loses people, how they react to the brand and how two or three edits compare. No video of anyone's face is stored. You get a readout you can act on, with a debrief call, before you commit the media budget. TV, online video, vertical social formats, cinema and animatics can all be tested.
When to test an ad
The earlier you test, the cheaper the fix. Most teams test at one of four points.
- Before the shootAnimatic or storyboard
- Check the idea and the story arc land before you spend on production.
- Before the media buyFinished cut
- Confirm the ad works, find the weak seconds and fix the edit while you still can.
- Choosing between editsTwo or three versions
- Each viewer sees one version, so you can compare them fairly and pick on evidence.
- Making cut-downs30s to 20s, 10s or 6s
- The second-by-second curve shows which moments carry the ad and which can go.
Ways to test an ad, compared
Ad testing has split into approaches that answer different questions. Here is where facial coding with real viewers fits.
| Approach | Real viewers? | What it measures | Examples |
|---|---|---|---|
| Predictive AI | No | A predicted score from a model trained on past ads. Results in minutes, useful for screening many ideas. | iMotions Predictive AI, System1 Test Your Ad Screen, Kantar LINK AI |
| Survey with self-reported emotion | Yes | What viewers say they felt, for example by choosing a face or word after watching. | System1 FaceTrace, standard ad surveys |
| Managed facial coding | Yes | Facial expressions coded while viewers watch, usually reported as proprietary scores. | Adverteyes (formerly Realeyes PreView), Element Human |
| Facial coding software | Your own sample | Expression analysis you run and interpret in-house. | iMotions with AFFDEX |
| EchoDepth | Yes | 44 FACS Action Units per frame, a second-by-second Emotional Response Curve with the method published, and the Cavefish Emotional Index from what viewers say. | Run as a study for you |
Descriptions of other providers are taken from their own websites in October 2026 and summarise their main public offer. Realeyes moved its ad testing business into a separate company, Adverteyes, in November 2025. Affectiva's ad testing is now offered through iMotions.
Why teams choose EchoDepth
Three things you won't get from a predicted score.
Measured on people
Every result comes from viewers who actually watched your ad, matched to your audience and screened for quality.
Open to inspection
Every score breaks down to the seconds and Action Units behind it. How the response curve is built is published, so your analysts can check our work.
Consent first
Viewers opt in to each study. No video of faces is stored, and we never code employees or students.
How a study runs
Remote, browser-based and managed for you from brief to debrief.
Brief and sample plan
Tell us the ad, the audience and the decision. We propose a sample, usually 15 or more viewers per audience segment.
Recruit and screen
Testers from our panel and partner panels, matched on age, gender, region and category use.
Viewers watch at home
Consent, a webcam setup check, a short neutral baseline, then your ad and a short survey.
Readout and debrief
The Emotional Response Curve, the Cavefish Emotional Index, peaks, drops, brand moment and stated vs felt, walked through on a call.
Ad testing guides
Format by format, plus the questions buyers ask before they commission a test.
- By format
- YouTube ad testing, TikTok, Reels and Shorts ad testing and TV ad pre-testing.
- Planning a test
- How to pre-test a video ad: the four weeks before launch and how much ad testing costs.
- Choosing a tool
- The best ad testing tools in 2026, and alternatives to System1, Realeyes and Affectiva.
- The science
- Is facial coding accurate?, attention vs emotion, emotional engagement scores, valence, arousal and dominance and AU12 and the Duchenne smile.
Ad testing questions
More on the measurement itself is in the methodology, and on costs in pricing and plans.
When should you pre-test an ad?
Before the money that's hardest to recover is spent. Test an animatic before the shoot if the idea is new, and test the finished cut before the media buy. Testing two or three edits side by side at either stage is the most common brief.
Can you test TikTok, Reels and YouTube Shorts ads?
Yes. Vertical ads are shown to viewers at their native aspect ratio, and the second-by-second curve is especially useful for the first two or three seconds, where short-form ads win or lose attention.
Can you test an animatic or storyboard?
Yes. Animatics produce a usable emotional curve, and testing at this stage lets you fix the story before production. Expect lower overall intensity than a finished film, so compare animatics with animatics.
How is ad pre-testing different from A/B testing on Meta or TikTok?
In-platform A/B tests compare live ads on clicks and conversions after you have paid for the media. Pre-testing shows the ad to a matched sample before launch and explains why it works, moment by moment, so you can fix it before spending.
How many viewers do I need to test an ad?
EchoDepth recommends 15 or more viewers per audience segment for each ad or edit. Every group you want to report on separately, such as under-35s and over-35s, is its own segment and needs its own 15. We agree the sample with you based on your audience and the decision you need to make.
What do I get at the end?
A report with the second-by-second Emotional Response Curve (valence, arousal and dominance), the peak and drop moments with the Action Units behind them, the brand moment, the Cavefish Emotional Index from what viewers say afterwards set against what their faces did, and a debrief call.