GPT-5.2 Instant vs Llama 3.1 405B

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 59. 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 40.6. The single biggest benchmark swing on the page is LiveCodeBench, 74 to 37.

GPT-5.2 Instant is the reasoning model in the pair, while Llama 3.1 405B 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.

Quick Verdict

Pick GPT-5.2 Instant if you want the stronger benchmark profile. Llama 3.1 405B only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

GPT-5.2 Instant

GPT-5.2 Instant

79.6

Llama 3.1 405B

53.9

83
Terminal-Bench 2.0
53
82
BrowseComp
58
74
OSWorld-Verified
52

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

Llama 3.1 405B

40.6

87
HumanEval
62
75
SWE-bench Verified
46
74
LiveCodeBench
37
77
SWE-bench Pro
43

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

Llama 3.1 405B

62.3

94
MMMU-Pro
60
92
OfficeQA Pro
65

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

Llama 3.1 405B

68.3

95
SimpleQA
68
93
MuSR
66
96
BBH
82
89
LongBench v2
68
84
MRCRv2
65

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

Llama 3.1 405B

53.2

98
MMLU
70
97
GPQA
70
95
SuperGPQA
68
93
OpenBookQA
66
88
MMLU-Pro
71
43
HLE
7
91
FrontierScience
65

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

Llama 3.1 405B

86

95
IFEval
86

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

Llama 3.1 405B

80.1

95
MGSM
84
94
MMLU-ProX
78

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

Llama 3.1 405B

74.9

99
AIME 2023
70
99
AIME 2024
72
98
AIME 2025
71
95
HMMT Feb 2023
66
97
HMMT Feb 2024
68
96
HMMT Feb 2025
67
96
BRUMO 2025
69
98
MATH-500
82

Frequently Asked Questions

Which is better, GPT-5.2 Instant or Llama 3.1 405B?

GPT-5.2 Instant is ahead overall, 85 to 59. The biggest single separator in this matchup is LiveCodeBench, where the scores are 74 and 37.

Which is better for knowledge tasks, GPT-5.2 Instant or Llama 3.1 405B?

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 53.2. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Instant or Llama 3.1 405B?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 versus 40.6. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Instant or Llama 3.1 405B?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 74.9. 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 Llama 3.1 405B?

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 versus 68.3. 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 Llama 3.1 405B?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 versus 53.9. 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 Llama 3.1 405B?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 62.3. 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 Llama 3.1 405B?

GPT-5.2 Instant has the edge for instruction following in this comparison, averaging 95 versus 86. 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 Llama 3.1 405B?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 versus 80.1. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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