# Claude Opus 4.8 vs Kimi K2.5 (Reasoning)

> Side-by-side benchmark comparison for Claude Opus 4.8 and Kimi K2.5 (Reasoning) across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-4-8-vs-kimi-k2-5-reasoning
- Last updated: October 10, 2026

- Shared sourced benchmarks: 6
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Claude Opus 4.8 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Claude Opus 4.8 has the higher overall point estimate 69.12 to 56.39. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in agentic, where the averages are 61.6 for Claude Opus 4.8 and 38.2 for Kimi K2.5 (Reasoning).
- The biggest single benchmark swing is Gert Labs in Agentic, with scores of 72.97% and 32.58%.
- Kimi K2.5 (Reasoning) is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Opus 4.8 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Opus 4.8 | Kimi K2.5 (Reasoning) |
|----------|----------|----------|
| Creator | Anthropic | Moonshot AI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 128K |
| Overall Score | 69.12 | 56.39 |
| Benchmarks Covered | 40 | 15 |
| Pricing (input/output) | $5.00 / $25.00 | $0.60 / $3.00 |

## Category Breakdown

### Agentic

- Winner: Directional only
- Claude Opus 4.8 public-lane score: 61.6 (Supported · #20/123)
- Kimi K2.5 (Reasoning) public-lane score: 38.2 (Estimated · #67/123)

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 21.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 74.6% | Coming soon | Coming soon |
| BrowseComp | 84.3% | 60.6% | Claude Opus 4.8 |
| DeepSearchQA | 93.1% | Coming soon | Coming soon |
| OSWorld-Verified | 83.4% | 63.3% | Claude Opus 4.8 |
| Finance Agent v2 | 53.9% | Coming soon | Coming soon |
| MCP Atlas | 82.2% | Coming soon | Coming soon |
| Toolathlon | 59.9% | Coming soon | Coming soon |
| Gert Labs | 72.97% | 32.58% | Claude Opus 4.8 |
| ResearchClawBench | 21.1% | Coming soon | Coming soon |
| OSWorld 2.0 | 20.6% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 71.9% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 50.8% | Coming soon |

### Coding

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 60.8 (Supported · #19/146)
- Kimi K2.5 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 88.6% | 76.8% | Claude Opus 4.8 |
| SWE-bench Pro | 69.2% | Coming soon | Coming soon |
| SWE Multilingual | 84.4% | Coming soon | Coming soon |
| SWE Multimodal | 38.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 74.6% | Coming soon | Coming soon |
| cursorBench31 | 58.4% | Coming soon | Coming soon |
| CursorBench 3.2 | 62.3% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 46.5% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.8% | Coming soon | Coming soon |
| SWE-bench (Vals) | 88.6% | Coming soon | Coming soon |
| PostTrainBench v1.1 | 32.9% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 85.0% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 50.8% | Coming soon |
| Vibe Code Bench | Coming soon | 17.54% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 62.9 (#24/28)
- Kimi K2.5 (Reasoning) public-lane score: 67.1 (Unranked · 1 rankable row)

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 72.1% | Coming soon | Coming soon |
| ARC-AGI-3 | 1.5% | Coming soon | Coming soon |
| ARC-AGI-1 | 92.50% | Coming soon | Coming soon |
| LongBench v2 | Coming soon | 61% | Coming soon |

### Multimodal & Grounded

- Winner: Directional only
- Claude Opus 4.8 public-lane score: 91.2 (#5/54)
- Kimi K2.5 (Reasoning) public-lane score: 69 (#33/54)

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | 66.2% | Coming soon | Coming soon |
| ScreenSpot Pro | 87.9% | Coming soon | Coming soon |
| CharXiv | 89.9% | 77.5% | Claude Opus 4.8 |
| CharXiv w/o tools | 80.5% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 78.5% | Coming soon |

### Knowledge

- Winner: Directional only
- Claude Opus 4.8 public-lane score: 70.7 (Supported · #14/177)
- Kimi K2.5 (Reasoning) public-lane score: 49.3 (Estimated · #80/177)

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 93.6% | 87.6% | Claude Opus 4.8 |
| GPQA-D | 93.6% | Coming soon | Coming soon |
| HLE | 57.9% | Coming soon | Coming soon |
| HLE w/o tools | 49.8% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 92.4% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 89.6% | Coming soon | Coming soon |
| MMLU-Pro | Coming soon | 87.1% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: Coming soon
- Kimi K2.5 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| INCLUDE | 87.6% | Coming soon | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 75.4 (#61/127)
- Kimi K2.5 (Reasoning) public-lane score: Coming soon

### Mathematics

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 65.7 (#2/7)
- Kimi K2.5 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Opus 4.8 | Kimi K2.5 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | 96.7% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 47.241% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 31.250% | Coming soon | Coming soon |
| AIME 2025 | Coming soon | 96.1% | Coming soon |
| HMMT Feb 2025 | Coming soon | 95.4% | Coming soon |

## FAQ

### Which is better overall, Claude Opus 4.8 or Kimi K2.5 (Reasoning)?

Claude Opus 4.8 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Claude Opus 4.8 and Kimi K2.5 (Reasoning)?

The widest category gap is in agentic, where the averages are 61.6 for Claude Opus 4.8 and 38.2 for Kimi K2.5 (Reasoning).

### How many benchmarks does Claude Opus 4.8 cover on BenchLM?

Claude Opus 4.8 currently has 40 sourced benchmark scores on BenchLM.

### How many benchmarks does Kimi K2.5 (Reasoning) cover on BenchLM?

Kimi K2.5 (Reasoning) currently has 15 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Opus 4.8 vs Kimi K2.5](/compare/claude-opus-4-8-vs-kimi-k2-5)
- [Kimi K2.5 (Reasoning) vs Kimi K2.5](/compare/kimi-k2-5-vs-kimi-k2-5-reasoning)
- [Claude Opus 4.8 vs Claude Opus 5.5](/compare/claude-opus-4-8-vs-claude-opus-5-5)
- [Kimi K2.5 (Reasoning) vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-kimi-k2-5-reasoning)

## Explore More

- [Claude Opus 4.8 profile](/models/claude-opus-4-8)
- [Kimi K2.5 (Reasoning) profile](/models/kimi-k2-5-reasoning)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)