GPT-5.2 Instant vs Claude Sonnet 4.5

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 76. 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 57.5. The single biggest benchmark swing on the page is HLE, 43 to 21.

Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $1.50 input / $6.00 output per 1M tokens for GPT-5.2 Instant. That is roughly 2.5x on output cost alone. GPT-5.2 Instant is the reasoning model in the pair, while Claude Sonnet 4.5 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. Claude Sonnet 4.5 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. Claude Sonnet 4.5 only becomes the better choice if you need the larger 200K context window or 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

Claude Sonnet 4.5

70.3

83
Terminal-Bench 2.0
69
82
BrowseComp
74
74
OSWorld-Verified
69

Coding

GPT-5.2 Instant

GPT-5.2 Instant

75.5

Claude Sonnet 4.5

57.5

87
HumanEval
87
75
SWE-bench Verified
66
74
LiveCodeBench
53
77
SWE-bench Pro
60

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

Claude Sonnet 4.5

91.4

94
MMMU-Pro
95
92
OfficeQA Pro
87

Reasoning

GPT-5.2 Instant

GPT-5.2 Instant

90.9

Claude Sonnet 4.5

86

95
SimpleQA
91
93
MuSR
89
96
BBH
88
89
LongBench v2
82
84
MRCRv2
81

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

Claude Sonnet 4.5

70.7

98
MMLU
95
97
GPQA
93
95
SuperGPQA
91
93
OpenBookQA
89
88
MMLU-Pro
84
43
HLE
21
91
FrontierScience
84

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

Claude Sonnet 4.5

90

95
IFEval
90

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

Claude Sonnet 4.5

88.4

95
MGSM
91
94
MMLU-ProX
87

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

Claude Sonnet 4.5

92.4

99
AIME 2023
97
99
AIME 2024
99
98
AIME 2025
98
95
HMMT Feb 2023
93
97
HMMT Feb 2024
95
96
HMMT Feb 2025
94
96
BRUMO 2025
96
98
MATH-500
88

Frequently Asked Questions

Which is better, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant is ahead overall, 85 to 76. The biggest single separator in this matchup is HLE, where the scores are 43 and 21.

Which is better for knowledge tasks, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 70.7. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for coding in this comparison, averaging 75.5 versus 57.5. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 92.4. Inside this category, MATH-500 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for reasoning in this comparison, averaging 90.9 versus 86. Inside this category, BBH is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for agentic tasks in this comparison, averaging 79.6 versus 70.3. 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 Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 91.4. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.2 Instant or Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for instruction following in this comparison, averaging 95 versus 90. 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 Claude Sonnet 4.5?

GPT-5.2 Instant has the edge for multilingual tasks in this comparison, averaging 94.4 versus 88.4. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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