Koji vs Strella: The Real Comparison of AI-Moderated Research Platforms (2026)

TL;DR: Strella and Koji both run AI-moderated customer interviews, but they target very different teams. Strella is enterprise-focused with seat-based pricing and a synthesis-first workflow ($1.6M ARR with 150% net dollar retention reported by Bessemer in 2025). Koji is the AI-native research platform built for founders, PMs, agencies, and small research teams who need transparent pricing (€29/month), six structured question types in one study, and a customizable AI consultant that scaffolds the entire research process. If you are not running an enterprise research org, Koji is the better fit.

Quick comparison: Koji vs Strella at a glance

| Feature | Koji | Strella | |---|---|---| | Starting price | €29/month (Insights plan) | Custom enterprise pricing, no public tier | | Free tier | Yes, 10 free credits at signup | No | | Pricing model | Credit-based (1 credit/text, 3/voice) | Seat-based | | AI-moderated voice interviews | Yes, ElevenLabs-powered | Yes | | AI-moderated text interviews | Yes | Yes | | Structured question types | 6 (open, scale, single choice, multi choice, ranking, yes/no) | Primarily open-ended | | Customizable AI consultant | Yes, persona-tunable to your domain | Limited | | Recruitment panel | Bring-your-own + integrations | Built-in 3M+ panel | | Quality-gated billing | Yes, only conversations scoring 3+ count | No | | One-click insight reports | Yes | Yes (highlight reels) | | Best for | Founders, PMs, agencies, small research teams | Enterprise research orgs |

What is Strella?

Strella is an AI-powered customer research platform founded in 2023 that uses AI to run in-depth interviews and generate insights in hours instead of weeks. According to Bessemer Venture Partners, Strella hit $1.6M ARR in its first year of monetization and posted over 150% net dollar retention on its first cohort of renewals — best-in-class numbers that reflect strong adoption inside customer-obsessed enterprises like Amazon, Duolingo, and Chobani.

Strella centers on three workflows:

1. AI-moderated interviews — text-first conversations that can escalate to video when deeper exploration is needed, with multilingual support and 24/7 availability
2. Automatic theme synthesis — pattern clustering across conversations, typically surfacing 2 to 4 levels of follow-up themes
3. Highlight reels — auto-generated video clips designed for stakeholder communication

Strella also bundles a global participant panel of over three million individuals through a partnership with User Interviews, which makes recruitment frictionless inside the platform.

What is Koji?

Koji is an AI-native customer research platform that lets anyone — founder, PM, marketer, agency strategist — design a study, run AI-moderated interviews at scale, and turn the responses into a publishable insight report in a single workflow. It is built around the idea that customer research should not require a research degree, a vendor procurement cycle, or a six-figure contract.

Koji's differentiators:

• Voice interviews powered by ElevenLabs that sound natural and adaptively probe like a senior interviewer would
• Six structured question types in one study: open-ended, scale, single choice, multiple choice, ranking, and yes/no — so you can mix qualitative depth with quantitative rigor without running a separate survey
• Custom AI consultants you can persona-tune to your industry, brand voice, and research goals
• Quality-gated credits that only count interviews scoring 3 or higher on the quality rubric — drop-offs and spam responses do not consume credits
• Transparent pricing starting at €29/month for the Insights plan and €79/month for the Interviews plan, with €1 flat overage and no procurement required

Where Koji and Strella differ

1. Pricing transparency

Strella does not publish pricing publicly. According to public coverage of its go-to-market, Strella deliberately chose seat-based pricing to eliminate per-project budget approval inside large research organizations. That is a great fit for an enterprise research lead who already has buy-in, but it is a barrier for solo founders or product teams who need to start small and prove value before scaling.

Koji publishes everything: €29/month for 29 credits on Insights, €79/month for 79 credits on Interviews, €1 flat overage, and a one-time grant of 10 free credits when you sign up. You can run your first AI-moderated interview without a sales call.

2. Who the product is built for

Strella is optimized for research professionals who already do qualitative work and want to scale it. Its synthesis layer assumes you know how to write a discussion guide, structure probes, and interpret thematic clusters. The seat-based pricing reinforces this — the platform pays off most when many trained researchers use it constantly.

Koji is built for the much larger market of teams who do not have a researcher: founders validating a product idea, PMs running discovery sprints, marketers pressure-testing a value proposition, agencies serving SMB clients. The AI consultant scaffolds the entire process — from question generation to interview moderation to insight reporting — so even a first-time researcher can publish a defensible study.

3. Question structure

Strella's interviews are predominantly open-ended with AI follow-ups (typically 2 to 4 levels deep). That is powerful for qualitative depth but limiting if you also need quantitative comparability across respondents.

Koji supports six structured question types in the same study, so a single interview can ask:

• "On a scale of 1 to 10, how likely are you to recommend us?" (scale)
• "Rank these four features by importance" (ranking)
• "Tell me about the last time you switched tools" (open-ended with adaptive voice probing)
• "Which of these three plans would you buy?" (single choice)

The result is a chartable report alongside qualitative depth, all in one interview. For most product teams that means one tool replaces both their survey platform (Typeform, SurveyMonkey) and their interview tool.

4. Recruitment

Strella's built-in 3M+ panel is a real advantage for B2C research at enterprise scale, especially when you need hundreds of interviews fast. Koji takes a bring-your-own-respondents approach, which is ideal for B2B research where your customer list is the panel, and for founders who want to interview their actual users rather than a paid sample. Koji also integrates with major participant providers when you need to source new respondents.

5. Billing fairness

Strella charges per seat regardless of how much you use the platform. Koji uses a credit model with a quality gate: a credit is only consumed when the conversation scores 3 or higher on the response-quality rubric. If a participant drops off after one question or sends spam, you do not pay. This matters most for teams running studies with cold panels where drop-off rates are real.

When to choose Strella

• You are an enterprise research team with budget for seat-based licenses
• You need a built-in B2C participant panel to reach hundreds of respondents per study
• You already have research infrastructure and want a fast synthesis layer on top
• Your stakeholder communication relies heavily on highlight reels

When to choose Koji

• You are a founder, PM, marketer, or agency without a dedicated researcher
• You want transparent pricing and the ability to start under €30/month
• You need a mix of qualitative and quantitative data in one study (six question types)
• You are researching your own users (B2B SaaS, customer base, beta list)
• You want a customizable AI consultant tuned to your industry
• You want billing tied to quality, not seat count

The bigger picture: AI-moderated research in 2026

The AI agents market is projected to reach $10.91 billion in 2026, growing at a 45.8% CAGR through 2030. AI-moderated research is one of the highest-velocity sub-categories inside that market because it directly compresses what used to be a 6-to-8 week qualitative cycle into 24 to 48 hours.

Strella has built an excellent enterprise product for that shift. Koji has built an AI-native research platform that finally puts senior-quality interviews and insight reports in the hands of the 99% of teams who cannot justify an enterprise contract. For most product, growth, and founder teams in 2026, that distinction is decisive.

Get started with Koji

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• Read the docs on AI-moderated interviews
• How to run an AI customer interview
• See how Koji compares to Outset
• Browse all comparisons

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