Model comparison
Claude Opus 4.5 Thinking vs Composer 2 Fast
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 4.5 Thinking #77 (Estimated); Composer 2 Fast unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Opus 4.5 Thinking and Composer 2 Fast share 0 comparable benchmark results. 0 of 8 categories are comparable. 16 results are unique to Claude Opus 4.5 Thinking; 1 to Composer 2 Fast.
Updated July 28, 2026- Shared results
- 0
- Claude Opus 4.5 Thinking only
- 16
- Composer 2 Fast only
- 1
- Comparable categories
- 0 / 8
Benchmark data for Claude Opus 4.5 Thinking and Composer 2 Fast is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 4.5 Thinking | Composer 2 Fast | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 4.5 ThinkingNot available | Composer 2 FastNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Claude Opus 4.5 ThinkingNot available | Composer 2 FastNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Opus 4.5 ThinkingNot available | Composer 2 FastNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Opus 4.5 Thinking200K | Composer 2 Fast200K | Listed context windows are equal. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Composer 2 Fast | Result |
|---|---|---|---|
| τ²-bench resultsSource | 89.5% | — | Not comparable |
Coding3 benchmarks
Reasoning2 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Composer 2 Fast | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 40.8% | — | Not comparable |
| AA-GPQA DiamondSource | 86.6% | — | Not comparable |
| AA-HLESource | 28.4% | — | Not comparable |
| AA-Omniscience IndexSource | 13.3% | — | Not comparable |
| AA-Omniscience AccuracySource | 45.7% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 59.8% | — | Not comparable |
| AA MMLU-ProSource | 89.5% | — | Not comparable |
Multilingual1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Composer 2 Fast | Result |
|---|---|---|---|
| AA Global-MMLU-LiteSource | 91.3% | — | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Opus 4.5 Thinking | Composer 2 Fast | Result |
|---|---|---|---|
| AA-IFBenchSource | 58.0% | — | Not comparable |
Frequently Asked Questions (2)
Can I compare Claude Opus 4.5 Thinking and Composer 2 Fast on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
Related Comparisons
Know when it’s worth switching models
The model to choose, the cheaper alternative, and the release we would wait on.
One email each week. Unsubscribe anytime.