Antithesis vs Horizon3.ai
Which Testing & QA AI tool is better in 2026?
Antithesis
Autonomous software testing platform built on deterministic simulation testing, which runs
Horizon3.ai
Autonomous penetration testing with NodeZero, run continuously at production scale
Side-by-side
Horizon3.ai is the more established option (raised $178.5M); pricing is comparable on both sides.
| Metric | Antithesis | Horizon3.ai |
|---|---|---|
| Taglinei | Autonomous software testing platform built on deterministic simulation testing, which runs | Autonomous penetration testing with NodeZero, run continuously at production scale |
| Foundedi | 2018🏆 | 2019 |
| HQi | — | San Francisco, United States |
| Employeesi | 11-50 | 201-500🏆 |
| Neuron scorei | 47 | 72🏆 |
| Total fundingi | $152M | $178.5M🏆 |
| Latest roundi | Seed | Series D · Jun 2025 |
| Valuationi | — | — |
| Cheapest paid plani | Pricing not disclosed | Pricing not disclosed |
| Free plani | ✓ | ✗ |
| Free triali | ✓ | ✓ |
| Top tier pricei | Pricing not disclosed | Pricing not disclosed |
| Pricing summaryi | Free | Enterprise · Contact sales |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Antithesis and Horizon3.ai.
| Capability | Antithesis | Horizon3.ai |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✓ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | — | — |
| Free plan | ✓ | ✗ |
| Free trial | ✓ | ✓ |
| Verified | ✗ | ✗ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Antithesis
- Offers a free plan
- More mature (2018)
🔵 Strengths of Horizon3.ai
- Has raised more capital ($178.5M vs $152M)
- Higher Neuron score (72 vs 47)
- Newer company (2019)
Which should you choose?
Choose Horizon3.ai if price matters most — it starts at Enterprise · Contact sales, which is friendlier for teams watching burn. Both AI Testing & QA tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Horizon3.ai if you want the most established option — it has raised $178.5M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
Frequently asked questions
Antithesis vs Horizon3.ai — which is better?
It depends on your priority. Antithesis is the leaner option; Horizon3.ai has broader feature depth. See the side-by-side table above.
Is Antithesis cheaper than Horizon3.ai?
No — Horizon3.ai's cheapest paid plan is Enterprise · Contact sales, while Antithesis's is Free.
Do Antithesis and Horizon3.ai offer free plans?
Antithesis: Yes, has a free plan. Horizon3.ai: Free trial only.
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