o3 vs Aion-2.0

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

o3 is clearly ahead on the aggregate, 70 to 58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

o3's sharpest advantage is in agentic, where it averages 69.9 against 51.7. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 71 to 48. 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.

o3 is also the more expensive model on tokens at $10.00 input / $40.00 output per 1M tokens, versus $0.80 input / $1.60 output per 1M tokens for Aion-2.0. That is roughly 25.0x on output cost alone. o3 is the reasoning model in the pair, while Aion-2.0 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. o3 gives you the larger context window at 200K, compared with 128K for Aion-2.0.

Quick Verdict

Pick o3 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.

Agentic

o3

o3

69.9

Aion-2.0

51.7

71
Terminal-Bench 2.0
48
75
BrowseComp
60
65
OSWorld-Verified
50

Coding

o3

o3

49.1

Aion-2.0

33.2

78
HumanEval
66
50
SWE-bench Verified
35
40
LiveCodeBench
29
58
SWE-bench Pro
37

Multimodal & Grounded

o3

o3

72.3

Aion-2.0

66

70
MMMU-Pro
61
75
OfficeQA Pro
72

Reasoning

o3

o3

82.6

Aion-2.0

70.3

84
SimpleQA
76
82
MuSR
74
86
BBH
76
82
LongBench v2
64
81
MRCRv2
65

Knowledge

o3

o3

66

Aion-2.0

54

86
MMLU
78
87
GPQA
77
85
SuperGPQA
75
83
OpenBookQA
75
75
MMLU-Pro
67
24
HLE
5
77
FrontierScience
66

Instruction Following

Aion-2.0

o3

85

Aion-2.0

93

85
IFEval
93

Multilingual

o3

o3

81.1

Aion-2.0

78.1

83
MGSM
80
80
MMLU-ProX
77

Mathematics

o3

o3

87.5

Aion-2.0

72.1

88
AIME 2023
74
90
AIME 2024
76
89
AIME 2025
75
84
HMMT Feb 2023
70
86
HMMT Feb 2024
72
85
HMMT Feb 2025
71
87
BRUMO 2025
73
88
MATH-500
71

Frequently Asked Questions

Which is better, o3 or Aion-2.0?

o3 is ahead overall, 70 to 58. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 71 and 48.

Which is better for knowledge tasks, o3 or Aion-2.0?

o3 has the edge for knowledge tasks in this comparison, averaging 66 versus 54. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, o3 or Aion-2.0?

o3 has the edge for coding in this comparison, averaging 49.1 versus 33.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, o3 or Aion-2.0?

o3 has the edge for math in this comparison, averaging 87.5 versus 72.1. Inside this category, MATH-500 is the benchmark that creates the most daylight between them.

Which is better for reasoning, o3 or Aion-2.0?

o3 has the edge for reasoning in this comparison, averaging 82.6 versus 70.3. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, o3 or Aion-2.0?

o3 has the edge for agentic tasks in this comparison, averaging 69.9 versus 51.7. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, o3 or Aion-2.0?

o3 has the edge for multimodal and grounded tasks in this comparison, averaging 72.3 versus 66. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, o3 or Aion-2.0?

Aion-2.0 has the edge for instruction following in this comparison, averaging 93 versus 85. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, o3 or Aion-2.0?

o3 has the edge for multilingual tasks in this comparison, averaging 81.1 versus 78.1. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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