Claude Opus 5.5 vs Step 5 Preview
Claude Opus 5.5 
Step 5 Preview Verdict
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 64.8.
- Claude Opus 5.5 (thinking) is stronger in composite, knowledge, multimodal, reasoning.
- Step 5 Preview is stronger in long context, coding.
- Step 5 Preview is 5.6× cheaper ($1.43 vs $8.00 per 1M blended).
- Step 5 Preview streams 1.7× faster (84 vs 48 tokens per second).
| Metric | Claude Opus 5.5 (thinking) | Step 5 Preview |
|---|---|---|
| BenchLeader Index | 70.7 | 64.8 |
| Composite score | 95.0 | 82.5 |
| Knowledge score | 85.0 | 71.0 |
| Long context score | 68.5 | 70.4 |
| Multimodal score | 71.9 | 60.3 |
| Reasoning score | 95.0 | 79.9 |
| Coding score | – | 68.8 |
| Blended price $/M | $8.00 | $1.43 |
| Output speed | 48 tok/s | 84 tok/s |
| Time to first answer | 4.2 s | 28.5 s |
| Context window | 1M | 1M |
| SciCode | – | 58.9% |
| AA Intelligence Index | 57.6 | 43.7 |
| AA-LCR | 84.7% | 88.3% |
| MMMU-Pro | 87.7% | 76.4% |
| AA-Omniscience | 46.4 | 16.4 |
| Humanity's Last Exam (AA) | 61.4% | 46.5% |
| SciCode (AA) | 66.9% | 58.9% |
| CritPt | 31.7% | 20.9% |
| GDPval (AA) | 67.3% | 53.3% |
| Terminal-Bench 4.0 (AA) | 59.6% | 33.3% |
| AutomationBench | 69.5% | 51.0% |
| GDP.pdf | 26.2% | 14.8% |
| MLCR | – | 16.7% |
| Harvey LAB | 91.2% | – |
| AA-Omniscience: accuracy | 66.2% | 41.5% |
| AA-Omniscience: non-hallucination | 41.4% | 57.0% |
| AA-Briefcase | 1822 | 1432 |
Data as of 2026-09-22. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 5.5 vs Step 5 Preview: questions
- Is Claude Opus 5.5 better than Step 5 Preview?
- Claude Opus 5.5 (thinking) leads on quality: 70.7 vs 64.8. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5.5 (thinking) is ahead overall as of 2026-09-22, but check the category scores for your use.
- Which is cheaper, Claude Opus 5.5 or Step 5 Preview?
- Step 5 Preview is cheaper: $1.43 against $8.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 5.5 or Step 5 Preview?
- Step 5 Preview streams faster: 84 against 48 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.