GPT-5.4 Pro vs LFM2.5-1.2B-Thinking

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

GPT-5.4 Pro is clearly ahead on the aggregate, 91 to 33. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.4 Pro's sharpest advantage is in coding, where it averages 87.4 against 8.2. The single biggest benchmark swing on the page is SWE-bench Pro, 89 to 7.

GPT-5.4 Pro is also the more expensive model on tokens at $30.00 input / $180.00 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. GPT-5.4 Pro gives you the larger context window at 1.05M, compared with 32K for LFM2.5-1.2B-Thinking.

Quick Verdict

Pick GPT-5.4 Pro if you want the stronger benchmark profile. LFM2.5-1.2B-Thinking only becomes the better choice if you want the cheaper token bill.

Agentic

GPT-5.4 Pro

GPT-5.4 Pro

87.4

LFM2.5-1.2B-Thinking

34.1

90
Terminal-Bench 2.0
34
88
BrowseComp
37
84
OSWorld-Verified
32

Coding

GPT-5.4 Pro

GPT-5.4 Pro

87.4

LFM2.5-1.2B-Thinking

8.2

95
HumanEval
17
86
SWE-bench Verified
10
86
LiveCodeBench
9
89
SWE-bench Pro
7

Multimodal & Grounded

GPT-5.4 Pro

GPT-5.4 Pro

94.9

LFM2.5-1.2B-Thinking

32.4

94
MMMU-Pro
27
96
OfficeQA Pro
39

Reasoning

GPT-5.4 Pro

GPT-5.4 Pro

96.1

LFM2.5-1.2B-Thinking

38.4

97
SimpleQA
29
95
MuSR
31
98
BBH
67
95
LongBench v2
39
97
MRCRv2
42

Knowledge

GPT-5.4 Pro

GPT-5.4 Pro

83.8

LFM2.5-1.2B-Thinking

27

99
MMLU
27
99
GPQA
26
97
SuperGPQA
24
94
OpenBookQA
22
94
MMLU-Pro
51
50
HLE
2
92
FrontierScience
31

Instruction Following

GPT-5.4 Pro

GPT-5.4 Pro

97

LFM2.5-1.2B-Thinking

72

97
IFEval
72

Multilingual

GPT-5.4 Pro

GPT-5.4 Pro

95.7

LFM2.5-1.2B-Thinking

60.7

97
MGSM
62
95
MMLU-ProX
60

Mathematics

GPT-5.4 Pro

GPT-5.4 Pro

98.2

LFM2.5-1.2B-Thinking

42.3

99
AIME 2023
28
99
AIME 2024
30
99
AIME 2025
29
96
HMMT Feb 2023
24
98
HMMT Feb 2024
26
97
HMMT Feb 2025
25
97
BRUMO 2025
27
99
MATH-500
61

Frequently Asked Questions

Which is better, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro is ahead overall, 91 to 33. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 89 and 7.

Which is better for knowledge tasks, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for knowledge tasks in this comparison, averaging 83.8 versus 27. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for coding in this comparison, averaging 87.4 versus 8.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for math in this comparison, averaging 98.2 versus 42.3. Inside this category, HMMT Feb 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for reasoning in this comparison, averaging 96.1 versus 38.4. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for agentic tasks in this comparison, averaging 87.4 versus 34.1. 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, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 94.9 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-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for instruction following in this comparison, averaging 97 versus 72. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.4 Pro or LFM2.5-1.2B-Thinking?

GPT-5.4 Pro has the edge for multilingual tasks in this comparison, averaging 95.7 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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