GPT-5.3 Instant vs GPT-4o

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 56. 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 32.2. The single biggest benchmark swing on the page is SWE-bench Verified, 76 to 20.

GPT-5.3 Instant is also the more expensive model on tokens at $1.75 input / $14.00 output per 1M tokens, versus $2.50 input / $10.00 output per 1M tokens for GPT-4o. GPT-5.3 Instant is the reasoning model in the pair, while GPT-4o 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-5.3 Instant if you want the stronger benchmark profile. GPT-4o only becomes the better choice if you want the cheaper token bill 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

GPT-4o

51.2

86
Terminal-Bench 2.0
49
82
BrowseComp
59
80
OSWorld-Verified
48

Coding

GPT-5.3 Instant

GPT-5.3 Instant

78.7

GPT-4o

32.2

88
HumanEval
58
76
SWE-bench Verified
20
75
LiveCodeBench
38
83
SWE-bench Pro
29

Multimodal & Grounded

GPT-5.3 Instant

GPT-5.3 Instant

95

GPT-4o

72.2

95
MMMU-Pro
74
95
OfficeQA Pro
70

Reasoning

GPT-5.3 Instant

GPT-5.3 Instant

94.2

GPT-4o

64.6

96
SimpleQA
64
94
MuSR
62
97
BBH
82
92
LongBench v2
62
94
MRCRv2
63

Knowledge

GPT-5.3 Instant

GPT-5.3 Instant

80.8

GPT-4o

47.4

99
MMLU
66
98
GPQA
66
96
SuperGPQA
64
94
OpenBookQA
62
89
MMLU-Pro
64
44
HLE
1
92
FrontierScience
58

Instruction Following

GPT-5.3 Instant

GPT-5.3 Instant

96

GPT-4o

82

96
IFEval
82

Multilingual

GPT-5.3 Instant

GPT-5.3 Instant

93.4

GPT-4o

75.5

96
MGSM
82
92
MMLU-ProX
72

Mathematics

GPT-5.3 Instant

GPT-5.3 Instant

97.2

GPT-4o

71.8

99
AIME 2023
66
99
AIME 2024
68
98
AIME 2025
67
95
HMMT Feb 2023
62
97
HMMT Feb 2024
64
96
HMMT Feb 2025
63
96
BRUMO 2025
65
98
MATH-500
80

Frequently Asked Questions

Which is better, GPT-5.3 Instant or GPT-4o?

GPT-5.3 Instant is ahead overall, 87 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 76 and 20.

Which is better for knowledge tasks, GPT-5.3 Instant or GPT-4o?

GPT-5.3 Instant has the edge for knowledge tasks in this comparison, averaging 80.8 versus 47.4. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3 Instant or GPT-4o?

GPT-5.3 Instant has the edge for coding in this comparison, averaging 78.7 versus 32.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3 Instant or GPT-4o?

GPT-5.3 Instant has the edge for math in this comparison, averaging 97.2 versus 71.8. 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 GPT-4o?

GPT-5.3 Instant has the edge for reasoning in this comparison, averaging 94.2 versus 64.6. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3 Instant or GPT-4o?

GPT-5.3 Instant has the edge for agentic tasks in this comparison, averaging 82.9 versus 51.2. 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 GPT-4o?

GPT-5.3 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 95 versus 72.2. 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 GPT-4o?

GPT-5.3 Instant has the edge for instruction following in this comparison, averaging 96 versus 82. 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 GPT-4o?

GPT-5.3 Instant has the edge for multilingual tasks in this comparison, averaging 93.4 versus 75.5. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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