Castelion vs Epirus
Which Defense AI AI tool is better in 2026?
Castelion
Mass-producing affordable hypersonic weapons for defense
Epirus
High-power microwave systems that disable drone swarms in flight
Side-by-side
Castelion is the more established option (raised $1.2B); pricing is comparable on both sides.
| Metric | Castelion | Epirus |
|---|---|---|
| Taglinei | Mass-producing affordable hypersonic weapons for defense | High-power microwave systems that disable drone swarms in flight |
| Foundedi | 2022 | 2018🏆 |
| HQi | El Segundo, US | Torrance, US |
| Employeesi | 201-500 | 201-500🏆 |
| Neuron scorei | 71🏆 | 59 |
| Total fundingi | $1.2B🏆 | $550M |
| Latest roundi | series-c · Aug 2026 | Series D · Mar 2025 |
| Valuationi | — | $1B🏆 |
| Cheapest paid plani | Pricing not disclosed | Pricing not disclosed |
| Free plani | ✗ | ✗ |
| Free triali | ✗ | ✗ |
| Top tier pricei | Pricing not disclosed | Pricing not disclosed |
| Pricing summaryi | Enterprise · Contact sales | Enterprise · Contact sales |
| Categoriesi |
Capability matrix
Developer-facing capabilities and access signals for Castelion and Epirus.
| Capability | Castelion | Epirus |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✗ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | — | — |
| Free plan | ✗ | ✗ |
| Free trial | ✗ | ✗ |
| Verified | ✗ | ✗ |
| Active deal | ✗ | ✗ |
🟢 Strengths of Castelion
- Has raised more capital ($1.2B vs $550M)
- Higher Neuron score (71 vs 59)
- Newer company (2022)
🔵 Strengths of Epirus
- More mature (2018)
Which should you choose?
Choose Epirus if price matters most — it starts at Enterprise · Contact sales, which is friendlier for teams watching burn. Both Defense AI tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Castelion if you want the most established option — it has raised $1.2B, 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
Castelion vs Epirus — which is better?
It depends on your priority. Castelion has raised more capital and is the more established option; Epirus has broader feature depth. See the side-by-side table above.
Is Castelion cheaper than Epirus?
No — Epirus's cheapest paid plan is Enterprise · Contact sales, while Castelion's is Enterprise · Contact sales.
Do Castelion and Epirus offer free plans?
Castelion: Paid only. Epirus: Paid only.
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