o3-mini vs Mercury 2

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

o3-mini is clearly ahead on the aggregate, 71 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

o3-mini's sharpest advantage is in coding, where it averages 55.6 against 41.1. The single biggest benchmark swing on the page is SWE-bench Pro, 57 to 43. Mercury 2 does hit back in multilingual, so the answer changes if that is the part of the workload you care about most.

o3-mini is also the more expensive model on tokens at $1.10 input / $4.40 output per 1M tokens, versus $0.25 input / $0.75 output per 1M tokens for Mercury 2. That is roughly 5.9x on output cost alone. o3-mini gives you the larger context window at 200K, compared with 128K for Mercury 2.

Quick Verdict

Pick o3-mini if you want the stronger benchmark profile. Mercury 2 only becomes the better choice if multilingual is the priority or you want the cheaper token bill.

Agentic

o3-mini

o3-mini

66.6

Mercury 2

63.7

67
Terminal-Bench 2.0
63
74
BrowseComp
67
61
OSWorld-Verified
62

Coding

o3-mini

o3-mini

55.6

Mercury 2

41.1

49.3
SWE-bench Verified
46
57
SWE-bench Pro
43
Coming soon
HumanEval
75
Coming soon
LiveCodeBench
38

Multimodal & Grounded

o3-mini

o3-mini

74.4

Mercury 2

68.3

73
MMMU-Pro
66
76
OfficeQA Pro
71

Reasoning

o3-mini

o3-mini

81.1

Mercury 2

80.1

82
LongBench v2
77
80
MRCRv2
76
Coming soon
SimpleQA
82
Coming soon
MuSR
82
Coming soon
BBH
87

Knowledge

o3-mini

o3-mini

70.8

Mercury 2

57.2

86.9
MMLU
78
77.2
GPQA
78
66
FrontierScience
69
Coming soon
SuperGPQA
76
Coming soon
OpenBookQA
74
Coming soon
MMLU-Pro
72
Coming soon
HLE
9

Instruction Following

o3-mini

o3-mini

93.9

Mercury 2

84

93.9
IFEval
84

Multilingual

Mercury 2

o3-mini

73

Mercury 2

79.7

73
MMLU-ProX
79
Coming soon
MGSM
81

Mathematics

o3-mini

o3-mini

87.3

Mercury 2

80.9

87.3
AIME 2024
83
Coming soon
AIME 2023
81
Coming soon
AIME 2025
82
Coming soon
HMMT Feb 2023
77
Coming soon
HMMT Feb 2024
79
Coming soon
HMMT Feb 2025
78
Coming soon
BRUMO 2025
80
Coming soon
MATH-500
82

Frequently Asked Questions

Which is better, o3-mini or Mercury 2?

o3-mini is ahead overall, 71 to 65. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 57 and 43.

Which is better for knowledge tasks, o3-mini or Mercury 2?

o3-mini has the edge for knowledge tasks in this comparison, averaging 70.8 versus 57.2. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, o3-mini or Mercury 2?

o3-mini has the edge for coding in this comparison, averaging 55.6 versus 41.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, o3-mini or Mercury 2?

o3-mini has the edge for math in this comparison, averaging 87.3 versus 80.9. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for reasoning, o3-mini or Mercury 2?

o3-mini has the edge for reasoning in this comparison, averaging 81.1 versus 80.1. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, o3-mini or Mercury 2?

o3-mini has the edge for agentic tasks in this comparison, averaging 66.6 versus 63.7. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, o3-mini or Mercury 2?

o3-mini has the edge for multimodal and grounded tasks in this comparison, averaging 74.4 versus 68.3. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, o3-mini or Mercury 2?

o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 84. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, o3-mini or Mercury 2?

Mercury 2 has the edge for multilingual tasks in this comparison, averaging 79.7 versus 73. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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