Claude Opus 4.8 vs Kimi K3
Claude Opus 4.8 (Anthropic) and Kimi K3 (Moonshot) compared on benchmarks, pricing, context window, and use-case rankings.
- Claude Opus 4.8 leads on overall intelligence (ECI 158 vs 158).
- Kimi K3 is cheaper on input tokens — $2.10 vs $5.00 per 1M.
- Kimi K3 has a larger context window (1M vs 1M tokens).
- Kimi K3 ranks higher for coding (97th vs 88th percentile).
| Attribute | Claude Opus 4.8 | Kimi K3 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 158 | 158 |
| Coding | 88 | 97 |
| Math | 88 | 81 |
| Reasoning & Knowledge | 77 | 73 |
| Agentic & Tools | 84 | 80 |
| Specifications | ||
| Developer | Anthropic | Moonshot |
| Family | Claude | Kimi |
| Released | May 28, 2026 | Jul 16, 2026 |
| Parameters | — | 2.8T |
| Availability | API access | Open weights (non-commercial) |
| Context window | 1M | 1M |
| Price — $/M input | $5.00 | $2.10 |
| Price — $/M output | $25.00 | $10.95 |
| Inputs | text, image, file | text, image, video |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 98% | 97% |
| APEX | 43% | 39% |
| ARC-AGI | 93% | 95% |
| ARC-AGI-2 | 72% | 60% |
| FrontierMath | 47% | — |
| FrontierMath Tier 4 | 31% | — |
| GPQA Diamond | 91% | 93% |
| GSO (code optimization) | 47% | — |
| Humanity's Last Exam | 49% | 47% |
| SciCode | 54% | 60% |
| SimpleBench | 65% | 61% |
| SimpleQA Verified | 53% | 51% |
| WebDev Arena | 1563 | 1674 |
| WeirdML | 83% | 83% |
| τ²-bench | 94% | — |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is Claude Opus 4.8 better than Kimi K3?
On Epoch AI's Capabilities Index, Claude Opus 4.8 scores higher (158) than Kimi K3 (158). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is cheaper, Claude Opus 4.8 or Kimi K3?
Kimi K3 is cheaper on input tokens at $2.10 per million, versus $5.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Opus 4.8 or Kimi K3?
Kimi K3 supports up to 1M tokens, compared with 1M for the other.
Which is better for coding, Claude Opus 4.8 or Kimi K3?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Kimi K3 ranks higher — 97th vs 88th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.