Mercury 2 vs LFM2.5-1.2B-Instruct

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

Mercury 2 is clearly ahead on the aggregate, 65 to 30. 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 reasoning, where it averages 80.1 against 32.1. The single biggest benchmark swing on the page is HumanEval, 75 to 14.

Mercury 2 is also the more expensive model on tokens at $0.25 input / $0.75 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for LFM2.5-1.2B-Instruct. That is roughly Infinityx on output cost alone. Mercury 2 is the reasoning model in the pair, while LFM2.5-1.2B-Instruct 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. Mercury 2 gives you the larger context window at 128K, compared with 32K for LFM2.5-1.2B-Instruct.

Quick Verdict

Pick Mercury 2 if you want the stronger benchmark profile. LFM2.5-1.2B-Instruct only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

Mercury 2

Mercury 2

63.7

LFM2.5-1.2B-Instruct

25.7

63
Terminal-Bench 2.0
22
67
BrowseComp
31
62
OSWorld-Verified
26

Coding

Mercury 2

Mercury 2

41.1

LFM2.5-1.2B-Instruct

7.2

75
HumanEval
14
46
SWE-bench Verified
9
38
LiveCodeBench
8
43
SWE-bench Pro
6

Multimodal & Grounded

Mercury 2

Mercury 2

68.3

LFM2.5-1.2B-Instruct

32.4

66
MMMU-Pro
27
71
OfficeQA Pro
39

Reasoning

Mercury 2

Mercury 2

80.1

LFM2.5-1.2B-Instruct

32.1

82
SimpleQA
24
82
MuSR
22
87
BBH
59
77
LongBench v2
34
76
MRCRv2
37

Knowledge

Mercury 2

Mercury 2

57.2

LFM2.5-1.2B-Instruct

26

78
MMLU
26
78
GPQA
25
76
SuperGPQA
23
74
OpenBookQA
21
72
MMLU-Pro
50
9
HLE
1
69
FrontierScience
30

Instruction Following

Mercury 2

Mercury 2

84

LFM2.5-1.2B-Instruct

80

84
IFEval
80

Multilingual

Mercury 2

Mercury 2

79.7

LFM2.5-1.2B-Instruct

60.7

81
MGSM
62
79
MMLU-ProX
60

Mathematics

Mercury 2

Mercury 2

80.9

LFM2.5-1.2B-Instruct

37

81
AIME 2023
24
83
AIME 2024
26
82
AIME 2025
25
77
HMMT Feb 2023
20
79
HMMT Feb 2024
22
78
HMMT Feb 2025
21
80
BRUMO 2025
23
82
MATH-500
54

Frequently Asked Questions

Which is better, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 is ahead overall, 65 to 30. The biggest single separator in this matchup is HumanEval, where the scores are 75 and 14.

Which is better for knowledge tasks, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for knowledge tasks in this comparison, averaging 57.2 versus 26. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for coding in this comparison, averaging 41.1 versus 7.2. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for math in this comparison, averaging 80.9 versus 37. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for reasoning in this comparison, averaging 80.1 versus 32.1. Inside this category, MuSR is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for agentic tasks in this comparison, averaging 63.7 versus 25.7. 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, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for multimodal and grounded tasks in this comparison, averaging 68.3 versus 32.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for instruction following in this comparison, averaging 84 versus 80. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Mercury 2 or LFM2.5-1.2B-Instruct?

Mercury 2 has the edge for multilingual tasks in this comparison, averaging 79.7 versus 60.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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