GPT-4.1 vs LFM2.5-1.2B-Thinking

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

GPT-4.1 is clearly ahead on the aggregate, 65 to 33. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-4.1's sharpest advantage is in coding, where it averages 51.7 against 8.2. The single biggest benchmark swing on the page is MMLU, 90.2 to 27. LFM2.5-1.2B-Thinking does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

GPT-4.1 is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for LFM2.5-1.2B-Thinking. That is roughly Infinityx on output cost alone. LFM2.5-1.2B-Thinking is the reasoning model in the pair, while GPT-4.1 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. GPT-4.1 gives you the larger context window at 1M, compared with 32K for LFM2.5-1.2B-Thinking.

Quick Verdict

Pick GPT-4.1 if you want the stronger benchmark profile. LFM2.5-1.2B-Thinking only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Agentic

GPT-4.1

GPT-4.1

64.7

LFM2.5-1.2B-Thinking

34.1

61
Terminal-Bench 2.0
34
73
BrowseComp
37
63
OSWorld-Verified
32

Coding

GPT-4.1

GPT-4.1

51.7

LFM2.5-1.2B-Thinking

8.2

54.6
SWE-bench Verified
10
51
SWE-bench Pro
7
Coming soon
HumanEval
17
Coming soon
LiveCodeBench
9

Multimodal & Grounded

GPT-4.1

GPT-4.1

73.6

LFM2.5-1.2B-Thinking

32.4

70
MMMU-Pro
27
78
OfficeQA Pro
39

Reasoning

GPT-4.1

GPT-4.1

80.9

LFM2.5-1.2B-Thinking

38.4

80
LongBench v2
39
82
MRCRv2
42
Coming soon
SimpleQA
29
Coming soon
MuSR
31
Coming soon
BBH
67

Knowledge

GPT-4.1

GPT-4.1

63.3

LFM2.5-1.2B-Thinking

27

90.2
MMLU
27
66.3
GPQA
26
61
FrontierScience
31
Coming soon
SuperGPQA
24
Coming soon
OpenBookQA
22
Coming soon
MMLU-Pro
51
Coming soon
HLE
2

Instruction Following

GPT-4.1

GPT-4.1

87.4

LFM2.5-1.2B-Thinking

72

87.4
IFEval
72

Multilingual

GPT-4.1

GPT-4.1

69

LFM2.5-1.2B-Thinking

60.7

69
MMLU-ProX
60
Coming soon
MGSM
62

Mathematics

LFM2.5-1.2B-Thinking

GPT-4.1

26.4

LFM2.5-1.2B-Thinking

42.3

26.4
AIME 2024
30
Coming soon
AIME 2023
28
Coming soon
AIME 2025
29
Coming soon
HMMT Feb 2023
24
Coming soon
HMMT Feb 2024
26
Coming soon
HMMT Feb 2025
25
Coming soon
BRUMO 2025
27
Coming soon
MATH-500
61

Frequently Asked Questions

Which is better, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 is ahead overall, 65 to 33. The biggest single separator in this matchup is MMLU, where the scores are 90.2 and 27.

Which is better for knowledge tasks, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for knowledge tasks in this comparison, averaging 63.3 versus 27. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for coding in this comparison, averaging 51.7 versus 8.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-4.1 or LFM2.5-1.2B-Thinking?

LFM2.5-1.2B-Thinking has the edge for math in this comparison, averaging 42.3 versus 26.4. Inside this category, AIME 2024 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for reasoning in this comparison, averaging 80.9 versus 38.4. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for agentic tasks in this comparison, averaging 64.7 versus 34.1. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for multimodal and grounded tasks in this comparison, averaging 73.6 versus 32.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for instruction following in this comparison, averaging 87.4 versus 72. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-4.1 or LFM2.5-1.2B-Thinking?

GPT-4.1 has the edge for multilingual tasks in this comparison, averaging 69 versus 60.7. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.