Claude Opus vs Kimi
Closed frontier against the open model that got closest to it. Kimi K3 ships open weights at roughly 2.8 trillion parameters with a million-token context. You can self-host it, which Opus 5 will never allow. Opus is still ahead on agentic reliability, but the gap is now small enough that data-residency or lock-in concerns can decide this outright.
| Claude Opus | Kimi | |
|---|---|---|
| Provider | Anthropic | Moonshot AI |
| Current release | Opus 5 | K3 |
| Tier | Frontier | Open weights |
| Context | 1M | 1M |
| Cost | Premium | Low cost |
| Modalities | text, vision | text, vision |
| Open weights | No | Yes |
Cost is a tier, not a quote, providers change prices often. Check Anthropic and Moonshot AI before you commit. Last updated 2026-09-04.
Which one to pick
Claude OpusAnthropic · Opus 5
Agentic coding and multi-step engineering work, near the ceiling, at half the price
Reach for it when- Agentic work where reliability is the whole point
- You want a vendor with a support relationship
KimiMoonshot AI · K3
Frontier-adjacent quality you can self-host, the open model closest to the closed leaders
Reach for it when- Data that cannot leave your infrastructure
- Avoiding vendor lock-in on principle
- Running at a scale where per-token pricing stops making sense
Related comparisons
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- Claude Opus vs Gemini ProTwo different bets.
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- Claude Fable vs Claude OpusThe within-Claude question.
- Claude Opus vs Claude SonnetThe one most Claude users get wrong by defaulting up.