GPT-5.3 Instant vs GPT-4o mini

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 52. 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 reasoning, where it averages 94.2 against 49.4. The single biggest benchmark swing on the page is MRCRv2, 94 to 50.

GPT-5.3 Instant is also the more expensive model on tokens at $1.75 input / $14.00 output per 1M tokens, versus $0.15 input / $0.60 output per 1M tokens for GPT-4o mini. That is roughly 23.3x on output cost alone. GPT-5.3 Instant is the reasoning model in the pair, while GPT-4o mini 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 mini 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 mini

50.9

86
Terminal-Bench 2.0
58
82
BrowseComp
49
80
OSWorld-Verified
44

Coding

GPT-5.3 Instant

GPT-5.3 Instant

78.7

GPT-4o mini

65

88
HumanEval
87.2
76
SWE-bench Verified
Coming soon
75
LiveCodeBench
Coming soon
83
SWE-bench Pro
65

Multimodal & Grounded

GPT-5.3 Instant

GPT-5.3 Instant

95

GPT-4o mini

60.2

95
MMMU-Pro
66
95
OfficeQA Pro
53

Reasoning

GPT-5.3 Instant

GPT-5.3 Instant

94.2

GPT-4o mini

49.4

96
SimpleQA
Coming soon
94
MuSR
Coming soon
97
BBH
Coming soon
92
LongBench v2
49
94
MRCRv2
50

Knowledge

GPT-5.3 Instant

GPT-5.3 Instant

80.8

GPT-4o mini

62

99
MMLU
82
98
GPQA
Coming soon
96
SuperGPQA
Coming soon
94
OpenBookQA
Coming soon
89
MMLU-Pro
Coming soon
44
HLE
Coming soon
92
FrontierScience
62

Instruction Following

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

96
IFEval
Coming soon

Multilingual

GPT-5.3 Instant

GPT-5.3 Instant

93.4

GPT-4o mini

74.7

96
MGSM
87
92
MMLU-ProX
68

Mathematics

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

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

Frequently Asked Questions

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

GPT-5.3 Instant is ahead overall, 87 to 52. The biggest single separator in this matchup is MRCRv2, where the scores are 94 and 50.

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

GPT-5.3 Instant has the edge for knowledge tasks in this comparison, averaging 80.8 versus 62. Inside this category, FrontierScience is the benchmark that creates the most daylight between them.

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

GPT-5.3 Instant has the edge for coding in this comparison, averaging 78.7 versus 65. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

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

GPT-5.3 Instant has the edge for reasoning in this comparison, averaging 94.2 versus 49.4. 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 GPT-4o mini?

GPT-5.3 Instant has the edge for agentic tasks in this comparison, averaging 82.9 versus 50.9. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.3 Instant or GPT-4o mini?

GPT-5.3 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 95 versus 60.2. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.

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

GPT-5.3 Instant has the edge for multilingual tasks in this comparison, averaging 93.4 versus 74.7. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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