Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.
Step 3.5 Flash is clearly ahead on the aggregate, 66 to 58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Step 3.5 Flash's sharpest advantage is in coding, where it averages 47.1 against 33.2. The single biggest benchmark swing on the page is LiveCodeBench, 45 to 29. 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.
Aion-2.0 is also the more expensive model on tokens at $0.80 input / $1.60 output per 1M tokens, versus $0.10 input / $0.30 output per 1M tokens for Step 3.5 Flash. That is roughly 5.3x on output cost alone. Step 3.5 Flash gives you the larger context window at 256K, compared with 128K for Aion-2.0.
Pick Step 3.5 Flash if you want the stronger benchmark profile. Aion-2.0 only becomes the better choice if instruction following is the priority.
Step 3.5 Flash
60.2
Aion-2.0
51.7
Step 3.5 Flash
47.1
Aion-2.0
33.2
Step 3.5 Flash
66.7
Aion-2.0
66
Step 3.5 Flash
78.3
Aion-2.0
70.3
Step 3.5 Flash
60.8
Aion-2.0
54
Step 3.5 Flash
87
Aion-2.0
93
Step 3.5 Flash
82.8
Aion-2.0
78.1
Step 3.5 Flash
84.5
Aion-2.0
72.1
Step 3.5 Flash is ahead overall, 66 to 58. The biggest single separator in this matchup is LiveCodeBench, where the scores are 45 and 29.
Step 3.5 Flash has the edge for knowledge tasks in this comparison, averaging 60.8 versus 54. Inside this category, MMLU-Pro is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for coding in this comparison, averaging 47.1 versus 33.2. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for math in this comparison, averaging 84.5 versus 72.1. Inside this category, MATH-500 is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for reasoning in this comparison, averaging 78.3 versus 70.3. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for agentic tasks in this comparison, averaging 60.2 versus 51.7. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for multimodal and grounded tasks in this comparison, averaging 66.7 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 87. Inside this category, IFEval is the benchmark that creates the most daylight between them.
Step 3.5 Flash has the edge for multilingual tasks in this comparison, averaging 82.8 versus 78.1. Inside this category, MGSM 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.