GPT-5.2 Instant vs LFM2.5-1.2B-Thinking

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

GPT-5.2 Instant is clearly ahead on the aggregate, 85 to 33. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.2 Instant's sharpest advantage is in coding, where it averages 75.5 against 8.2. The single biggest benchmark swing on the page is MMLU, 98 to 27.

GPT-5.2 Instant is also the more expensive model on tokens at $1.50 input / $6.00 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-5.2 Instant gives you the larger context window at 128K, compared with 32K for LFM2.5-1.2B-Thinking.

Quick Verdict

Pick GPT-5.2 Instant 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-5.2 Instant

GPT-5.2 Instant

79.6

LFM2.5-1.2B-Thinking

34.1

83
Terminal-Bench 2.0
34
82
BrowseComp
37
74
OSWorld-Verified
32

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

LFM2.5-1.2B-Thinking

8.2

87
HumanEval
17
75
SWE-bench Verified
10
74
LiveCodeBench
9
77
SWE-bench Pro
7

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

LFM2.5-1.2B-Thinking

32.4

94
MMMU-Pro
27
92
OfficeQA Pro
39

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

LFM2.5-1.2B-Thinking

38.4

95
SimpleQA
29
93
MuSR
31
96
BBH
67
89
LongBench v2
39
84
MRCRv2
42

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

LFM2.5-1.2B-Thinking

27

98
MMLU
27
97
GPQA
26
95
SuperGPQA
24
93
OpenBookQA
22
88
MMLU-Pro
51
43
HLE
2
91
FrontierScience
31

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

LFM2.5-1.2B-Thinking

72

95
IFEval
72

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

LFM2.5-1.2B-Thinking

60.7

95
MGSM
62
94
MMLU-ProX
60

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

LFM2.5-1.2B-Thinking

42.3

99
AIME 2023
28
99
AIME 2024
30
98
AIME 2025
29
95
HMMT Feb 2023
24
97
HMMT Feb 2024
26
96
HMMT Feb 2025
25
96
BRUMO 2025
27
98
MATH-500
61

Frequently Asked Questions

Which is better, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant is ahead overall, 85 to 33. The biggest single separator in this matchup is MMLU, where the scores are 98 and 27.

Which is better for knowledge tasks, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 27. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 versus 8.2. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 42.3. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 versus 38.4. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 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-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 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-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for instruction following in this comparison, averaging 95 versus 72. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.2 Instant or LFM2.5-1.2B-Thinking?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 versus 60.7. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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