Koji vs Amplitude: AI Customer Research vs Product Analytics (2026)

TL;DR: Amplitude is the gold-standard product analytics platform — it shows you what users click, where they drop off, and which cohorts retain. Koji is an AI-native customer research platform — it shows you why users behave that way, in their own words, via AI-moderated voice interviews. They are complements, not substitutes. Most product teams need both. Koji starts at €29/month self-serve; Amplitude starts free for 1,000 monthly tracked users (MTUs) with paid Plus, Growth, and Enterprise tiers above that.

Product teams have been told for a decade that "data-driven" means "look at the funnel." That advice is half-right and half-dangerous. Amplitude funnels show you that 47% of new users drop off at the workspace setup step. They cannot tell you why. The "why" lives in conversations with the users who dropped off — and that is exactly what Koji is built for.

This guide compares the two platforms feature-by-feature, explains where each is genuinely better, and gives a decision framework for product teams trying to allocate research budget between behavioral analytics and qualitative research.

Quick comparison table

| Feature | Koji | Amplitude | |---|---|---| | Primary use case | Qualitative AI-moderated customer interviews | Quantitative product behavior analytics | | Answers | "Why did they do that?" | "What did they do?" | | Data source | Voice/text conversations + structured questions | Event streams from web/mobile SDKs | | Sample size | 5–100 interviews per study | Millions of events per day | | AI moderator | Yes — ElevenLabs voice, real-time probing | No — Amplitude analyzes events, doesn't talk to users | | AI Feedback module | N/A — entire product is AI research | Yes — analyzes open-ended survey responses | | Surveys & polls | Built-in, blended with interviews | Amplitude Guides and Surveys (Plus add-on) | | Session replay | No (not the use case) | Yes — Session Replay add-on | | Feature experimentation | No | Yes — Amplitude Experiment | | Recruiting non-users | Yes — share an interview link anywhere | No — only people on your product | | Starting price | €29/month, self-serve, 29 credits | Free up to 1,000 MTUs; Plus from ~$49/month | | Best for | Discovery, JTBD, churn, concept testing, NPS follow-ups | Funnel analysis, retention curves, A/B tests, dashboards |

The core difference: behavioral data vs. human voice

Amplitude is a behavioral analytics platform. It listens to your product's event stream — clicks, page views, sign-ups, conversions — and crunches those events into funnels, retention charts, and user cohorts. As of April 2026, Amplitude's suite includes Analytics, Guides and Surveys, Feature Experiment, Web Experiment, Activation, AI Feedback, AI Assistant, and Session Replay (Amplitude Pricing).

Koji is a qualitative research platform. It does not listen to events — it talks to people. The AI moderator runs voice or text interviews, asks the questions you wrote, follows up on vague answers in real time, and clusters the resulting transcripts into themes. The output is verbatim quotes, jobs-to-be-done patterns, and qualitative reports — not retention curves.

The analogy product leaders should hold in their head: Amplitude is a Fitbit. It tells you exactly how many steps you took. Koji is a conversation with a coach who asks why you stopped going to the gym.

What Amplitude is genuinely best at

Amplitude is a category-defining product. We use behavioral analytics ourselves and recommend you do too. Where Amplitude wins:

• Funnel analysis at scale. "Of users who signed up, how many activated within 7 days?" — Amplitude crushes this question.
• Retention curves. D1, D7, D30 cohort retention is the bread-and-butter Amplitude chart and remains the best in class.
• A/B test telemetry. Amplitude Experiment lets you ship experiments and see which variant wins on hard behavioral metrics.
• Real-time event volume. Amplitude can ingest billions of events per day. Koji is not built to handle that.
• Session Replay. Watch an actual user session frame-by-frame to debug a UX issue.
• Cross-platform tracking. Web + iOS + Android + server events stitched together by user ID.

If your job is "I need to know which onboarding step is breaking" or "Did variant B beat variant A on activation?" — buy Amplitude. Koji does not solve those problems.

What Koji is genuinely best at

Koji answers the questions Amplitude cannot:

1. Why did they drop off?

Amplitude shows you that 47% of users abandon onboarding at the team-invite step. Koji asks 15 of those users why — and the AI probes when answers are vague. You will get answers like "I don't want to invite my team before I know if the product works" or "I am evaluating this solo before pitching it internally." Those are roadmap-changing insights. Amplitude only shows the drop-off bar.

2. Talking to non-users

Amplitude can only see people who installed the SDK and used your product. The much larger group — bouncers, churned users, prospects evaluating competitors — are invisible. Koji is built to reach them via shared interview links, CSV imports of churned users, or panel recruiting through participant recruitment platforms.

3. Mixed-methods qualitative + structured

Koji blends 6 structured question types — open-ended, scale, single-choice, multiple-choice, ranking, yes/no — with AI-moderated probing in the same session. So you can ask "On a 1–10 scale, how satisfied are you with onboarding?" and immediately probe "You gave it a 4 — walk me through what made it difficult." Amplitude's Guides and Surveys can run a poll, but it cannot probe the answer.

4. Discovery and JTBD work

For genuinely generative research — when you don't yet know what to instrument — Koji is the right tool. Amplitude is built around tracking events you've already decided are important. If you don't know what events matter yet, you need conversations first. See the jobs-to-be-done interview guide for how this works in practice.

5. Win/loss and churn analysis

Win/loss interviews and churn interviews require talking to humans, not analyzing event streams. Amplitude can show you that a customer churned. Koji helps you understand why.

Where Amplitude's qualitative features fall short

Amplitude has invested in qualitative-adjacent features — Guides and Surveys, AI Feedback, AI Assistant — and they are improving every quarter. But they are designed as supplements to Amplitude's analytics core, not as standalone research tools. Specifically:

• AI Feedback can theme open-ended survey responses, but it does not probe in real time during the response. It analyzes after the fact.
• Guides and Surveys are in-product polls and onboarding tooltips. They are not a replacement for sit-down interviews with structured discussion guides.
• No voice modality. Amplitude is text and event-stream only. There is no voice interview equivalent to Koji's ElevenLabs voice engine.
• No participant recruitment workflow. Amplitude assumes the user is already in your product. Koji assumes you may need to talk to people who aren't.
• No async interview format. Koji participants take an interview on their own schedule via a shared link. Amplitude surveys fire when the user is in your app.

If you tried to run a discovery study using only Amplitude Surveys, you would get truncated, unprobed data and no qualitative depth. That is not Amplitude's job — and it shouldn't be.

Pricing comparison

| | Koji | Amplitude | |---|---|---| | Free tier | 10 credits at signup | Starter — free up to 1,000 MTUs | | Entry plan | Insights — €29/month, 29 credits | Plus — from ~$49/month for 1,000 MTUs | | Mid plan | Interviews — €79/month, 79 credits | Growth — custom pricing | | Enterprise | Custom (€500+/mo equivalent) | Enterprise — custom pricing | | Cost driver | Per-credit (1 text chat = 1 credit, 1 voice interview = 3 credits) | Per MTU + module add-ons (Session Replay, AI Feedback, Guides) | | Hidden costs | None | Add-on modules, MTU overages, custom event volumes | | Self-serve | Yes, full | Yes for Starter/Plus; Growth and Enterprise require sales |

For a small product team, Koji at €29–€79/month is a complete research stack. Amplitude is essentially free for early-stage products under 1,000 MTUs, and scales with growth. The two budgets do not overlap and should not be compared as substitutes.

A reasonable allocation: a seed-stage SaaS company spends $0 on Amplitude (Starter tier) and €29–€79/month on Koji to do customer discovery. A Series B SaaS company spends $20K–$100K/year on Amplitude (analytics + Session Replay + Experiment) and €948/year on Koji for ongoing qualitative work. Both are right at their stage.

Decision framework

Use Amplitude when:

• You need to measure funnel conversion, retention, or activation
• You are running A/B tests and need behavioral lift data
• You want to understand what users did (not why)
• You need session replay to debug specific UX issues
• You have an installed SDK and an event-rich product

Use Koji when:

• You need to understand why a behavior is happening
• You are doing customer discovery, JTBD, or generative research
• You want to talk to churned users or non-users
• You need structured questions plus open probing in one session
• You need a thematic report from 20 interviews in 2 days

Use both when:

• You are building any product more complex than a landing page
• Your funnel data and your qualitative data should triangulate — Amplitude tells you the symptom, Koji finds the cause

A workflow that uses both

The highest-leverage product team workflow we see:

1. Amplitude flags a problem. Drop-off at step 3 of onboarding spikes 8 percentage points week-over-week.
2. Koji explains it. Ship a Koji study to the last 50 users who hit step 3 and dropped, asking "walk me through what happened when you got to the team invite screen." The AI probes. Two days later, you have a thematic report with verbatim quotes.
3. You ship a fix. The fix is informed by both the what (Amplitude told you exactly which step broke) and the why (Koji told you it broke because users feel premature about inviting teammates).
4. Amplitude validates. A/B test the new flow in Amplitude Experiment. Behavior moves.

That full loop — quant flags, qual explains, ship, quant validates — is the modern product team operating model. Both tools earn their seat.

Why teams add Koji to their existing Amplitude stack

According to industry data, the top three generative AI use cases are content creation (71%), code generation (58%), and customer interaction (54%). Customer-interaction AI — which is exactly what Koji does — is now mainstream, and product teams are realizing their analytics-only stack has a qualitative blind spot.

Research from B2B SaaS benchmarks shows the median company now spends $2.00 to acquire $1.00 of new ARR with a 23-month CAC payback period. Misallocating that acquisition budget — because you don't understand why users churn or bounce — is one of the most expensive mistakes a SaaS team can make. Amplitude shows you the bleeding. Koji helps you stop it.

Try Koji free

If your team has Amplitude installed and you've been wondering "why are people dropping off at step 3?" — that's the question Koji was built to answer. Start a free study with 10 credits at signup. Pull your last 30 churned users from Amplitude (or any CSV), import them into a Koji study, and run an AI-moderated interview campaign in an afternoon.

For more on the methodology, read how to analyze customer interview data, how to run AI-powered interviews at scale, or the user research complete guide.