GPT-5.3 Instant vs Claude 4.1 Opus

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

GPT-5.3 Instant is clearly ahead on the aggregate, 87 to 64. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3 Instant's sharpest advantage is in coding, where it averages 78.7 against 44. The single biggest benchmark swing on the page is SWE-bench Pro, 83 to 47.

GPT-5.3 Instant is the reasoning model in the pair, while Claude 4.1 Opus 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 4.1 Opus gives you the larger context window at 200K, compared with 128K for GPT-5.3 Instant.

Quick Verdict

Pick GPT-5.3 Instant if you want the stronger benchmark profile. Claude 4.1 Opus 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-5.3 Instant

GPT-5.3 Instant

82.9

Claude 4.1 Opus

58.7

86
Terminal-Bench 2.0
58
82
BrowseComp
62
80
OSWorld-Verified
57

Coding

GPT-5.3 Instant

GPT-5.3 Instant

78.7

Claude 4.1 Opus

44

88
HumanEval
68
76
SWE-bench Verified
48
75
LiveCodeBench
40
83
SWE-bench Pro
47

Multimodal & Grounded

GPT-5.3 Instant

GPT-5.3 Instant

95

Claude 4.1 Opus

80.7

95
MMMU-Pro
82
95
OfficeQA Pro
79

Reasoning

GPT-5.3 Instant

GPT-5.3 Instant

94.2

Claude 4.1 Opus

72.9

96
SimpleQA
74
94
MuSR
72
97
BBH
81
92
LongBench v2
71
94
MRCRv2
71

Knowledge

GPT-5.3 Instant

GPT-5.3 Instant

80.8

Claude 4.1 Opus

57.6

99
MMLU
76
98
GPQA
76
96
SuperGPQA
74
94
OpenBookQA
72
89
MMLU-Pro
75
44
HLE
11
92
FrontierScience
68

Instruction Following

GPT-5.3 Instant

GPT-5.3 Instant

96

Claude 4.1 Opus

83

96
IFEval
83

Multilingual

GPT-5.3 Instant

GPT-5.3 Instant

93.4

Claude 4.1 Opus

81.8

96
MGSM
85
92
MMLU-ProX
80

Mathematics

GPT-5.3 Instant

GPT-5.3 Instant

97.2

Claude 4.1 Opus

77.7

99
AIME 2023
76
99
AIME 2024
78
98
AIME 2025
77
95
HMMT Feb 2023
72
97
HMMT Feb 2024
74
96
HMMT Feb 2025
73
96
BRUMO 2025
75
98
MATH-500
81

Frequently Asked Questions

Which is better, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant is ahead overall, 87 to 64. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 83 and 47.

Which is better for knowledge tasks, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for knowledge tasks in this comparison, averaging 80.8 versus 57.6. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for coding in this comparison, averaging 78.7 versus 44. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for math in this comparison, averaging 97.2 versus 77.7. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for reasoning in this comparison, averaging 94.2 versus 72.9. Inside this category, MRCRv2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for agentic tasks in this comparison, averaging 82.9 versus 58.7. 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-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 95 versus 80.7. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for instruction following in this comparison, averaging 96 versus 83. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.3 Instant or Claude 4.1 Opus?

GPT-5.3 Instant has the edge for multilingual tasks in this comparison, averaging 93.4 versus 81.8. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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