Koji is an AI-native research platform that runs AI-moderated voice and text interviews with your real customers and turns them into thematic analysis and reports. Entropik''s Decode is a unified insights platform whose signature is Emotion AI — facial coding, eye tracking, and voice analytics layered on top of interviews and usability tests. The choice comes down to a simple question: do you need to measure biometric emotion signals, or do you need deeper conversations and faster, defensible decisions? For most product, UX, and research teams, the second is what actually moves the roadmap — and that is Koji''s core. For brand and advertising teams that specifically want facial-expression and attention metrics, Entropik has a specialized niche.
The 2026 context: conversation depth is beating instrumentation
The research shift in 2026 is unambiguous. 95% of researchers use or experiment with AI tools, AI customer research is the default discovery method for 81% of research teams and 73% of UX teams, and AI-conversation tooling grew 4.2x year over year even as panel spend dropped 34%. Teams are seeing cost-per-insight fall 71% and time-to-decision drop to a median of 3.2 days versus 26 days for panel studies.
Notice what is pulling budget: AI-moderated interviewing, not biometric add-ons. The bottleneck teams actually feel is running enough good conversations and synthesizing them fast — not measuring micro-expressions. That framing matters when you compare Koji and Entropik.
Koji vs Entropik Decode at a glance
| Dimension | Koji | Entropik (Decode) |
|---|---|---|
| Core method | AI-moderated voice + text interviews with real customers | Interviews + usability tests with Emotion AI (facial coding, eye tracking, voice) |
| Signature capability | Deep conversational probing + automatic thematic analysis | Multimodal Emotion AI and behavioral metrics |
| Question types | 6 structured types blended into one conversation | Surveys, interviews, usability tests with biometric layers |
| Analysis | Two-cycle thematic coding with grounded verbatim quotes | Emotion/sentiment scoring, attention, facial coding |
| Primary buyer | Product, UX, founders, growth, research teams | Brand, advertising, and CX teams wanting biometrics |
| Pricing | Transparent, self-serve, free tier, from EUR 29/mo | Subscription, sales-led, custom |
| Time to first insight | Hours | Days, depending on setup |
Where Koji wins
1. The interview is the product, not an afterthought. Koji''s AI moderator adapts in real time — probing when a respondent hesitates, asking for specifics when they skim, and surfacing tensions when they contradict themselves. That is where the insight lives. Entropik layers emotion metrics onto sessions, but a confident facial-coding score cannot tell you why a user is frustrated the way a good follow-up question can. See how AI interviewers work and AI-moderated interviews.
2. Qual plus quant without extra hardware. Koji blends six structured question types — open-ended, scale, single choice, multiple choice, ranking, and yes/no — into one conversation, producing chartable metrics and the reasons behind them. No webcams, eye-tracking calibration, or biometric consent overhead required. More in the structured questions guide.
3. Analysis that is defensible and traceable. Koji auto-codes transcripts with descriptive and in-vivo themes grounded in verbatim quotes, clusters them across interviews, and produces a one-click report plus an interrogatable AI research consultant. Emotion scores are interesting; a coded, quote-backed theme is what you take to a roadmap review. See thematic analysis and our complete guide to AI qualitative research.
4. Faster and radically simpler to adopt. Koji is self-serve and starts free, scaling from EUR 29/mo, with a quality gate so you only pay for conversations that clear the bar. Entropik is enterprise, sales-led, and biometric setups add methodological and privacy complexity. If your goal is decisions this week, simplicity wins.
Where Entropik fits
Entropik Decode is a specialist tool, and its Emotion AI is genuinely differentiated. It reports high-accuracy detection of emotions from facial coding and voice, plus eye tracking and attention analytics across interviews, ads, and usability tests. If you are a brand, advertising, or media-testing team whose research questions are specifically about non-verbal reaction — which frame of an ad holds attention, where the eye goes on a shelf design, the emotional arc of a creative — Entropik offers instrumentation most conversational tools do not. That specialization comes with enterprise pricing, heavier setup, and biometric-data considerations.
Which should you choose?
- Choose Koji if you need to understand why customers behave the way they do, run more interviews faster, and get defensible, quote-backed insight without biometric overhead — the everyday reality for product, UX, founder, and research teams.
- Choose Entropik if your research is specifically about measuring emotional and attentional response — ad testing, creative evaluation, shelf and packaging attention — and you have the budget and mandate for biometric methods.
For teams whose north star is shipping the right thing quickly, deeper conversations beat more sensors. That is why AI-moderated interviewing, not biometrics, is the line item growing 4.2x. If you are comparing across the category, see AI-moderated interview platforms, are AI-moderated interviews reliable, and best AI user research tools.
Emotion scores vs stated reasons: what actually drives a decision
Biometric signals feel scientific, and in the right context they are. But there is a gap between detecting an emotion and explaining it. Entropik can tell you a user''s expression registered frustration at second 34 of a flow. Koji can tell you the user said, in their own words, that they expected the discount to apply at checkout and felt tricked when it did not — a specific, fixable, roadmap-ready finding. For most product and UX decisions, the stated reason is more actionable than the measured affect, because you can only ship against a reason, not against a sentiment curve.
There is also an adoption cost to biometrics that is easy to underrate. Facial coding and eye tracking need cameras, calibration, lighting, and explicit biometric-data consent — each a point of participant drop-off and a compliance question for your legal team. Koji''s AI-moderated voice and text interviews run in any browser with no special hardware, which keeps completion rates high and setup near-zero. When the goal is more good conversations, fewer friction points wins.
Where each tool earns its keep
Think of it as two different jobs. Entropik earns its keep when the research question is fundamentally non-verbal — which second of an ad holds attention, whether a packaging redesign draws the eye, the emotional arc of a brand film. Those are real questions that conversation alone answers less well. Koji earns its keep on the far larger set of everyday questions — why users churn, which feature to build next, what is breaking in onboarding, how a value proposition lands — where the answer lives in what people say and why. Most software teams live overwhelmingly in that second world, which is why AI-moderated interviewing, not biometrics, is the fastest-growing research line item in 2026. For the broader landscape, see best AI tools for UX research.
Get to the "why" — start free
Koji runs AI-moderated interviews that probe like your best researcher, then delivers automatic thematic analysis and a shareable report — no moderator, no biometric rig, no research expertise required. Try Koji free and turn a research question into decision-ready insight in hours.
