Mercury 2 vs Gemini 2.5 Flash

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

Mercury 2 is clearly ahead on the aggregate, 65 to 49. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Mercury 2's sharpest advantage is in mathematics, where it averages 80.9 against 59.4. The single biggest benchmark swing on the page is MuSR, 82 to 46.

Mercury 2 is also the more expensive model on tokens at $0.25 input / $0.75 output per 1M tokens, versus $0.15 input / $0.60 output per 1M tokens for Gemini 2.5 Flash. Mercury 2 is the reasoning model in the pair, while Gemini 2.5 Flash 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. Gemini 2.5 Flash gives you the larger context window at 1M, compared with 128K for Mercury 2.

Quick Verdict

Pick Mercury 2 if you want the stronger benchmark profile. Gemini 2.5 Flash only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.

Agentic

Mercury 2

Mercury 2

63.7

Gemini 2.5 Flash

46.5

63
Terminal-Bench 2.0
44
67
BrowseComp
58
62
OSWorld-Verified
41

Coding

Mercury 2

Mercury 2

41.1

Gemini 2.5 Flash

21.7

75
HumanEval
42
46
SWE-bench Verified
23
38
LiveCodeBench
18
43
SWE-bench Pro
25

Multimodal & Grounded

Mercury 2

Mercury 2

68.3

Gemini 2.5 Flash

67.7

66
MMMU-Pro
69
71
OfficeQA Pro
66

Reasoning

Mercury 2

Mercury 2

80.1

Gemini 2.5 Flash

59.2

82
SimpleQA
48
82
MuSR
46
87
BBH
75
77
LongBench v2
68
76
MRCRv2
68

Knowledge

Mercury 2

Mercury 2

57.2

Gemini 2.5 Flash

40.5

78
MMLU
50
78
GPQA
49
76
SuperGPQA
47
74
OpenBookQA
45
72
MMLU-Pro
64
9
HLE
1
69
FrontierScience
49

Instruction Following

Mercury 2

Mercury 2

84

Gemini 2.5 Flash

79

84
IFEval
79

Multilingual

Mercury 2

Mercury 2

79.7

Gemini 2.5 Flash

70.8

81
MGSM
74
79
MMLU-ProX
69

Mathematics

Mercury 2

Mercury 2

80.9

Gemini 2.5 Flash

59.4

81
AIME 2023
50
83
AIME 2024
52
82
AIME 2025
51
77
HMMT Feb 2023
46
79
HMMT Feb 2024
48
78
HMMT Feb 2025
47
80
BRUMO 2025
49
82
MATH-500
72

Frequently Asked Questions

Which is better, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 is ahead overall, 65 to 49. The biggest single separator in this matchup is MuSR, where the scores are 82 and 46.

Which is better for knowledge tasks, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for knowledge tasks in this comparison, averaging 57.2 versus 40.5. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for coding in this comparison, averaging 41.1 versus 21.7. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for math in this comparison, averaging 80.9 versus 59.4. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for reasoning in this comparison, averaging 80.1 versus 59.2. Inside this category, MuSR is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for agentic tasks in this comparison, averaging 63.7 versus 46.5. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for multimodal and grounded tasks in this comparison, averaging 68.3 versus 67.7. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for instruction following in this comparison, averaging 84 versus 79. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Mercury 2 or Gemini 2.5 Flash?

Mercury 2 has the edge for multilingual tasks in this comparison, averaging 79.7 versus 70.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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