DeepSeek V3.1 (Reasoning) vs LFM2.5-1.2B-Instruct

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

DeepSeek V3.1 (Reasoning) is clearly ahead on the aggregate, 41 to 30. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

DeepSeek V3.1 (Reasoning)'s sharpest advantage is in agentic, where it averages 44.2 against 25.7. The single biggest benchmark swing on the page is LongBench v2, 57 to 34. LFM2.5-1.2B-Instruct does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.

DeepSeek V3.1 (Reasoning) 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. DeepSeek V3.1 (Reasoning) gives you the larger context window at 128K, compared with 32K for LFM2.5-1.2B-Instruct.

Quick Verdict

Pick DeepSeek V3.1 (Reasoning) if you want the stronger benchmark profile. LFM2.5-1.2B-Instruct only becomes the better choice if instruction following is the priority or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

44.2

LFM2.5-1.2B-Instruct

25.7

42
Terminal-Bench 2.0
22
48
BrowseComp
31
44
OSWorld-Verified
26

Coding

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

19.9

LFM2.5-1.2B-Instruct

7.2

26
HumanEval
14
14
SWE-bench Verified
9
16
LiveCodeBench
8
25
SWE-bench Pro
6

Multimodal & Grounded

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

41.5

LFM2.5-1.2B-Instruct

32.4

37
MMMU-Pro
27
47
OfficeQA Pro
39

Reasoning

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

45.8

LFM2.5-1.2B-Instruct

32.1

32
SimpleQA
24
30
MuSR
22
64
BBH
59
57
LongBench v2
34
56
MRCRv2
37

Knowledge

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

32.8

LFM2.5-1.2B-Instruct

26

34
MMLU
26
33
GPQA
25
31
SuperGPQA
23
29
OpenBookQA
21
53
MMLU-Pro
50
10
HLE
1
37
FrontierScience
30

Instruction Following

LFM2.5-1.2B-Instruct

DeepSeek V3.1 (Reasoning)

70

LFM2.5-1.2B-Instruct

80

70
IFEval
80

Multilingual

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

62.1

LFM2.5-1.2B-Instruct

60.7

64
MGSM
62
61
MMLU-ProX
60

Mathematics

DeepSeek V3.1 (Reasoning)

DeepSeek V3.1 (Reasoning)

46.1

LFM2.5-1.2B-Instruct

37

34
AIME 2023
24
36
AIME 2024
26
35
AIME 2025
25
30
HMMT Feb 2023
20
32
HMMT Feb 2024
22
31
HMMT Feb 2025
21
33
BRUMO 2025
23
62
MATH-500
54

Frequently Asked Questions

Which is better, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) is ahead overall, 41 to 30. The biggest single separator in this matchup is LongBench v2, where the scores are 57 and 34.

Which is better for knowledge tasks, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for knowledge tasks in this comparison, averaging 32.8 versus 26. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for coding in this comparison, averaging 19.9 versus 7.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for math in this comparison, averaging 46.1 versus 37. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for reasoning in this comparison, averaging 45.8 versus 32.1. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for agentic tasks in this comparison, averaging 44.2 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, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for multimodal and grounded tasks in this comparison, averaging 41.5 versus 32.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

LFM2.5-1.2B-Instruct has the edge for instruction following in this comparison, averaging 80 versus 70. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, DeepSeek V3.1 (Reasoning) or LFM2.5-1.2B-Instruct?

DeepSeek V3.1 (Reasoning) has the edge for multilingual tasks in this comparison, averaging 62.1 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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