Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.
Claude Sonnet 4.5 is clearly ahead on the aggregate, 76 to 58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 4.5's sharpest advantage is in multimodal & grounded, where it averages 91.4 against 66. The single biggest benchmark swing on the page is MMMU-Pro, 95 to 61. Aion-2.0 does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.
Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.80 input / $1.60 output per 1M tokens for Aion-2.0. That is roughly 9.4x on output cost alone. Claude Sonnet 4.5 gives you the larger context window at 200K, compared with 128K for Aion-2.0.
Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. Aion-2.0 only becomes the better choice if instruction following is the priority or you want the cheaper token bill.
Claude Sonnet 4.5
70.3
Aion-2.0
51.7
Claude Sonnet 4.5
57.5
Aion-2.0
33.2
Claude Sonnet 4.5
91.4
Aion-2.0
66
Claude Sonnet 4.5
86
Aion-2.0
70.3
Claude Sonnet 4.5
70.7
Aion-2.0
54
Claude Sonnet 4.5
90
Aion-2.0
93
Claude Sonnet 4.5
88.4
Aion-2.0
78.1
Claude Sonnet 4.5
92.4
Aion-2.0
72.1
Claude Sonnet 4.5 is ahead overall, 76 to 58. The biggest single separator in this matchup is MMMU-Pro, where the scores are 95 and 61.
Claude Sonnet 4.5 has the edge for knowledge tasks in this comparison, averaging 70.7 versus 54. Inside this category, FrontierScience is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for coding in this comparison, averaging 57.5 versus 33.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for math in this comparison, averaging 92.4 versus 72.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for reasoning in this comparison, averaging 86 versus 70.3. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for agentic tasks in this comparison, averaging 70.3 versus 51.7. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for multimodal and grounded tasks in this comparison, averaging 91.4 versus 66. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
Aion-2.0 has the edge for instruction following in this comparison, averaging 93 versus 90. Inside this category, IFEval is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for multilingual tasks in this comparison, averaging 88.4 versus 78.1. Inside this category, MGSM is the benchmark that creates the most daylight between them.
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