Comparison
Kallina AI vs Retell AI: Complete Comparison for 2026
Retell AI is a developer platform for building voice agents with per-minute pricing. Kallina offers managed voice AI with fixed plans. Here is how they stack up.
Feature Comparison
| Feature | Kallina AI | Retell AI |
|---|---|---|
| Starting PriceRetell's advertised $0.055 is just the engine; real cost is 2-3x with LLM, TTS, and telephony | $99/mo (Starter) | $0.055/min engine + components = $0.11-0.15/min total (pay-as-you-go) |
| Free Tier | No (free demo available) | Yes ($10 free credit) |
| Languages | 30+ | English-focused, growing multilingual |
| Conversation Designer | Template-based setup | Visual flow builder |
| LatencyBoth offer competitive latency | ~500ms | ~600ms (proprietary voice engine) |
| Target User | Businesses & agencies | Developers & product teams |
| CRM Integrations | Built-in (Syrve, AmoCRM, Zoho) | Via API webhooks and Zapier |
| Pricing ModelPredictable costs for businesses | Fixed monthly (minutes included) | Per-minute usage-based |
Pros & Cons
Kallina AI
Cons
- ✗ No free tier, starts at $99/mo
- ✗ Less granular developer control vs Retell's API
- ✗ No visual flow builder for conversation design
Retell AI
Pros
- ✓ Free tier with $10 credit to start
- ✓ Component-based pricing: $0.055/min engine + LLM + TTS + telephony ($0.11-0.15/min total)
- ✓ Industry-leading ~600ms latency with proprietary turn-taking models
- ✓ Visual conversation flow builder with multi-prompt stateful agents
- ✓ Strong developer documentation, SDKs, and 4.8/5 rating (929 reviews)
- ✓ 6 pre-built agent templates (receptionist, appointment setter, lead qual, etc.)
Cons
- ✗ Per-minute costs become expensive at high volume (2,000 min/month on Build plan = ~$565/month total)
- ✗ Enterprise plan requires $3,000+/month spend for volume discounts
- ✗ 31 languages supported but English-optimized
- ✗ Requires developer knowledge for advanced customization
- ✗ Add-on costs pile up: knowledge base +$0.005/min, PII removal +$0.01/min, denoising +$0.005/min
Our Verdict
Retell AI is a solid choice for developer teams that want to build custom voice agents with a visual flow builder and flexible per-minute pricing. Its free tier and low entry cost make it great for prototyping. Kallina is a better fit for businesses that want a fully managed voice AI solution with predictable pricing, multilingual support, and ready-made business integrations without needing a development team.
Last updated: 4 Ebrel 2026
Prices and features were last verified on April 4, 2026. Visit Retell AI for current pricing.