Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.
Claude Sonnet 4.6 is clearly ahead on the aggregate, 78 to 66. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 4.6's sharpest advantage is in multimodal & grounded, where it averages 91.9 against 66.7. The single biggest benchmark swing on the page is MMMU-Pro, 95 to 64.
Claude Sonnet 4.6 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.10 input / $0.30 output per 1M tokens for Step 3.5 Flash. That is roughly 50.0x on output cost alone. Step 3.5 Flash gives you the larger context window at 256K, compared with 200K for Claude Sonnet 4.6.
Pick Claude Sonnet 4.6 if you want the stronger benchmark profile. Step 3.5 Flash only becomes the better choice if you want the cheaper token bill or you need the larger 256K context window.
Claude Sonnet 4.6
71.1
Step 3.5 Flash
60.2
Claude Sonnet 4.6
60
Step 3.5 Flash
47.1
Claude Sonnet 4.6
91.9
Step 3.5 Flash
66.7
Claude Sonnet 4.6
87.6
Step 3.5 Flash
78.3
Claude Sonnet 4.6
71.8
Step 3.5 Flash
60.8
Claude Sonnet 4.6
91
Step 3.5 Flash
87
Claude Sonnet 4.6
89.7
Step 3.5 Flash
82.8
Claude Sonnet 4.6
94.1
Step 3.5 Flash
84.5
Claude Sonnet 4.6 is ahead overall, 78 to 66. The biggest single separator in this matchup is MMMU-Pro, where the scores are 95 and 64.
Claude Sonnet 4.6 has the edge for knowledge tasks in this comparison, averaging 71.8 versus 60.8. Inside this category, MMLU is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for coding in this comparison, averaging 60 versus 47.1. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for math in this comparison, averaging 94.1 versus 84.5. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for reasoning in this comparison, averaging 87.6 versus 78.3. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for agentic tasks in this comparison, averaging 71.1 versus 60.2. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for multimodal and grounded tasks in this comparison, averaging 91.9 versus 66.7. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for instruction following in this comparison, averaging 91 versus 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.
Claude Sonnet 4.6 has the edge for multilingual tasks in this comparison, averaging 89.7 versus 82.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.
Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.
Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.