GPT-5.2 Instant vs GPT-5.2-Codex

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

GPT-5.2 Instant and GPT-5.2-Codex finish on the same overall score, so this is less about a single winner and more about where the edge shows up. The headline says tie; the benchmark table is where the real choice happens.

GPT-5.2-Codex is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $1.50 input / $6.00 output per 1M tokens for GPT-5.2 Instant. GPT-5.2-Codex gives you the larger context window at 400K, compared with 128K for GPT-5.2 Instant.

Quick Verdict

Treat this as a split decision. GPT-5.2 Instant makes more sense if knowledge is the priority or you want the cheaper token bill; GPT-5.2-Codex is the better fit if agentic is the priority or you need the larger 400K context window.

Agentic

GPT-5.2-Codex

GPT-5.2 Instant

79.6

GPT-5.2-Codex

87

83
Terminal-Bench 2.0
90
82
BrowseComp
85
74
OSWorld-Verified
85

Coding

GPT-5.2-Codex

GPT-5.2 Instant

75.5

GPT-5.2-Codex

76

87
HumanEval
95
75
SWE-bench Verified
76
74
LiveCodeBench
66
77
SWE-bench Pro
86

Multimodal & Grounded

GPT-5.2 Instant

GPT-5.2 Instant

93.1

GPT-5.2-Codex

87.6

94
MMMU-Pro
84
92
OfficeQA Pro
92

Reasoning

GPT-5.2-Codex

GPT-5.2 Instant

90.9

GPT-5.2-Codex

92

95
SimpleQA
95
93
MuSR
93
96
BBH
90
89
LongBench v2
90
84
MRCRv2
91

Knowledge

GPT-5.2 Instant

GPT-5.2 Instant

79.8

GPT-5.2-Codex

72.5

98
MMLU
99
97
GPQA
97
95
SuperGPQA
95
93
OpenBookQA
93
88
MMLU-Pro
80
43
HLE
26
91
FrontierScience
86

Instruction Following

GPT-5.2 Instant

GPT-5.2 Instant

95

GPT-5.2-Codex

92

95
IFEval
92

Multilingual

GPT-5.2 Instant

GPT-5.2 Instant

94.4

GPT-5.2-Codex

88.4

95
MGSM
91
94
MMLU-ProX
87

Mathematics

GPT-5.2 Instant

GPT-5.2 Instant

97.2

GPT-5.2-Codex

95.4

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

Frequently Asked Questions

Which is better, GPT-5.2 Instant or GPT-5.2-Codex?

GPT-5.2 Instant and GPT-5.2-Codex are tied on overall score, so the right pick depends on which category matters most for your use case.

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

GPT-5.2 Instant has the edge for knowledge tasks in this comparison, averaging 79.8 versus 72.5. Inside this category, HLE is the benchmark that creates the most daylight between them.

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

GPT-5.2-Codex has the edge for coding in this comparison, averaging 76 versus 75.5. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

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

GPT-5.2 Instant has the edge for math in this comparison, averaging 97.2 versus 95.4. 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 GPT-5.2-Codex?

GPT-5.2-Codex has the edge for reasoning in this comparison, averaging 92 versus 90.9. Inside this category, MRCRv2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.2 Instant or GPT-5.2-Codex?

GPT-5.2-Codex has the edge for agentic tasks in this comparison, averaging 87 versus 79.6. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.2 Instant or GPT-5.2-Codex?

GPT-5.2 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 93.1 versus 87.6. 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 GPT-5.2-Codex?

GPT-5.2 Instant has the edge for instruction following in this comparison, averaging 95 versus 92. 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 GPT-5.2-Codex?

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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