GPT-5.2 Instant vs o3

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 70. 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 49.1. The single biggest benchmark swing on the page is LiveCodeBench, 74 to 40.

o3 is also the more expensive model on tokens at $10.00 input / $40.00 output per 1M tokens, versus $1.50 input / $6.00 output per 1M tokens for GPT-5.2 Instant. That is roughly 6.7x on output cost alone. o3 gives you the larger context window at 200K, compared with 128K for GPT-5.2 Instant.

Quick Verdict

Pick GPT-5.2 Instant if you want the stronger benchmark profile. o3 only becomes the better choice if you need the larger 200K context window.

Agentic

GPT-5.2 Instant

GPT-5.2 Instant

79.6

o3

69.9

83
Terminal-Bench 2.0
71
82
BrowseComp
75
74
OSWorld-Verified
65

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

o3

49.1

87
HumanEval
78
75
SWE-bench Verified
50
74
LiveCodeBench
40
77
SWE-bench Pro
58

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

o3

72.3

94
MMMU-Pro
70
92
OfficeQA Pro
75

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

o3

82.6

95
SimpleQA
84
93
MuSR
82
96
BBH
86
89
LongBench v2
82
84
MRCRv2
81

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

o3

66

98
MMLU
86
97
GPQA
87
95
SuperGPQA
85
93
OpenBookQA
83
88
MMLU-Pro
75
43
HLE
24
91
FrontierScience
77

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

o3

85

95
IFEval
85

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

o3

81.1

95
MGSM
83
94
MMLU-ProX
80

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

o3

87.5

99
AIME 2023
88
99
AIME 2024
90
98
AIME 2025
89
95
HMMT Feb 2023
84
97
HMMT Feb 2024
86
96
HMMT Feb 2025
85
96
BRUMO 2025
87
98
MATH-500
88

Frequently Asked Questions

Which is better, GPT-5.2 Instant or o3?

GPT-5.2 Instant is ahead overall, 85 to 70. The biggest single separator in this matchup is LiveCodeBench, where the scores are 74 and 40.

Which is better for knowledge tasks, GPT-5.2 Instant or o3?

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 66. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Instant or o3?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 versus 49.1. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Instant or o3?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 87.5. 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 o3?

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 versus 82.6. 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 o3?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 versus 69.9. 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 o3?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 72.3. 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 o3?

GPT-5.2 Instant has the edge for instruction following in this comparison, averaging 95 versus 85. 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 o3?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 versus 81.1. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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