TL;DR
Koji and Useberry both help product teams learn from users, but they capture different layers of insight.
- Useberry is an unmoderated UX testing platform. Import a Figma, Adobe XD, or Sketch prototype, set up tasks, and collect quantitative click-path data — task success rates, completion times, drop-off points, first-click tests, card sorts, and tree tests — plus heatmaps and recordings.
- Koji is an AI-native customer research platform. It runs AI-moderated voice and text interviews, probes up to three follow-ups per question, themes every transcript automatically, and ships a stakeholder-ready report that explains why users did what they did.
Useberry tells you whether a prototype works — did users complete the task, where did they hesitate, how many clicks did it take. Koji tells you why it works or fails — what they expected, what confused them, what they would pay for. Useberry measures the click path; Koji captures the human behind it. The best discovery programs use both.
This post breaks down what each tool is genuinely good at, where each falls short, real 2026 pricing, and the eight scenarios where teams pick one over the other.
Quick comparison: Koji vs Useberry
| Capability | Koji | Useberry |
|---|---|---|
| Primary methodology | AI-moderated voice + text interviews | Unmoderated prototype + usability testing |
| Captures the why | Yes — AI probes up to 3 follow-ups per question | Limited — optional open-text, no live probing |
| Figma / prototype click-path testing | No — interviews, not prototype tasks | Yes — core strength (Figma, XD, Sketch) |
| Structured questions | 6 types: open_ended, scale, single_choice, multiple_choice, ranking, yes_no | First-click, card sort, tree test, task metrics |
| Automatic thematic analysis | Yes, across every transcript | Quantitative metrics + heatmaps |
| Adaptive follow-up | Yes — AI digs into every answer | No — tasks are fixed and unmoderated |
| Works without a prototype | Yes — concept, pricing, JTBD with no design | No — needs an importable prototype |
| Voice interviews | Yes — natural spoken conversation | No — task-based, mostly silent |
| Pricing | Transparent per-credit (29-79 EUR/mo) | Free (10 responses/mo); Growth 83 EUR/mo; Business 659 EUR/mo |
| Best for | The why, discovery, validation, pricing | Measuring whether a prototype flow works |
What Useberry is genuinely good at
Useberry has become a leader in unmoderated, prototype-first UX testing. Its strengths in 2026:
- Deep Figma integration. Connect once, pick a prototype, and Useberry keeps it in sync so teams iterate without re-uploading. It is recognized for some of the deepest click-path analysis on Figma prototypes available.
- Quantitative usability metrics. It automatically captures task success rates, completion times, drop-off points, and misclicks — the numbers you need to prove a flow works.
- Built-in research methods. First-click tests, card sorting, tree testing, and single-task usability tests are all native, covering the core unmoderated toolkit.
- Visual analytics. Heatmaps, click maps, path analysis, and session recordings make it easy to see where users hesitated or went off-path.
- Fast and scalable. Unmoderated tests run around the clock with no scheduling, so you can collect hundreds of responses quickly.
If your question is does this prototype flow work and where do users get stuck, Useberry answers it well.
Where Useberry falls short
Useberry is unmoderated and task-based by design, and that design has clear limits:
- It struggles to explain the why. You can see a 30% drop-off on step three of a flow, but an unmoderated task cannot adaptively ask "what were you expecting to happen there?" Optional open-text boxes are not a conversation — there is no probing, no follow-up, no chasing the real reason.
- It needs a prototype. Useberry requires an importable design. You cannot use it to validate a raw concept, a pricing model, or a positioning statement before anything is designed — exactly when research reshapes the most decisions.
- No real voice interviews. Testing is task-driven and largely silent. You lose the tone, hesitation, and spontaneous detail that spoken answers carry. See why this matters in voice vs text interviews.
- Response-capped pricing. The free plan stops at 10 responses per month, and meaningful volume sits on the Growth and Business tiers — costs scale with response count, not with insight.
- Behavioral, not motivational. Like all unmoderated UX tools, Useberry is strong on what users did in a flow and thin on why they wanted it in the first place.
What Koji does that Useberry cannot
Koji covers the motivational layer that an unmoderated task test cannot reach.
- AI-moderated interviews at scale. Koji runs the same structured interview with every participant over voice or text, probing up to three follow-ups per question to chase the why behind every answer — the adaptive depth a fixed task list cannot deliver.
- Six structured question types. Combine open-ended probing with
scale,single_choice,multiple_choice,ranking, andyes_noquestions for quotable depth and chartable numbers in one study. - Automatic thematic analysis. Every transcript is themed automatically — no manual tagging or spreadsheet coding. See the methodology in our thematic analysis guide.
- Works with no prototype at all. Because Koji is a shared link, you can validate the concept, the price, and the value proposition long before a designer opens Figma. See concept testing methodology and our guide to prototype testing and concept validation.
- One-click reports. Question to insight in hours, with themes, quotes, and quantitative breakdowns generated automatically.
For where usability testing fits alongside interviews, see the usability testing guide and usability testing questions.
Real 2026 pricing: Koji vs Useberry
Useberry prices by response volume:
- Free — 10 responses/month, 1 project
- Growth — about 83 EUR/month (billed yearly), 300 responses/month, unlimited projects
- Business — about 659 EUR/month (billed yearly), 2,000 responses/month, 5 seats
- Enterprise — custom
Koji uses transparent, per-credit pricing:
- Insights — 29 EUR/month (29 credits included)
- Interviews — 79 EUR/month (79 credits included)
- Free tier — 10 credits on signup, no card required
- Credit costs: text = 1, voice = 3, report refresh = 5. Only conversations that score 3+ on the quality gate consume credits, so junk responses never burn budget.
The real decision is not price, it is layer. Useberry charges you per response to measure a prototype flow. Koji charges you per credit to understand the person using it.
8 scenarios: which tool wins
- "Can users complete checkout in my Figma prototype?" → Useberry. Task metrics on a prototype are its core.
- "Why did users hesitate on the plan-selection screen?" → Koji. Interview them and hear the reason.
- "We have no design yet — is this idea worth building?" → Koji. Useberry needs a prototype; Koji does not.
- "Run a first-click test and a tree test on this IA." → Useberry. Purpose-built unmoderated methods.
- "Would users pay 19 EUR or 39 EUR for this?" → Koji. Pricing is a conversation, not a click-path metric.
- "Measure task success across three design variants." → Useberry. Quantitative comparison wins.
- "What job are users hiring this product to do?" → Koji. JTBD is interview territory.
- "I need quotes and themes for the stakeholder deck." → Koji. Automatic thematic analysis and a one-click report.
When to use Koji and Useberry together
The strongest discovery loop runs both:
- Koji frames the problem — before design starts, run AI-moderated interviews to learn what users actually need, what they would pay, and which jobs matter.
- Useberry tests the prototype — once a Figma flow exists, measure task success, completion time, and drop-off to confirm the design works.
- Koji explains the drop-off — when Useberry shows users stalling on a specific step, interview that cohort to learn why and feed the answer into the next iteration.
Useberry measures the flow. Koji explains the human. Together they turn "32% dropped off at step three" into "32% dropped off because they expected a guest-checkout option, and here are 9 quotes proving it."
The bottom line
Useberry is a strong unmoderated prototype-testing tool — the right choice for measuring whether a Figma flow works and where users get stuck. What it cannot do is hold a conversation. Koji is the AI-native research platform built for exactly that: voice and text interviews, adaptive probing, six structured question types, automatic themes, and reports in hours — with or without a prototype.
If your next design decision depends on understanding user motivation, not just task metrics, start free with Koji and run your first AI-moderated study today. Ten credits, no card, your first insights this afternoon.
