GPT-5.3 Instant vs Nemotron 3 Ultra 500B

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 43.8. The single biggest benchmark swing on the page is SWE-bench Pro, 83 to 47.

Nemotron 3 Ultra 500B gives you the larger context window at 10M, compared with 128K for GPT-5.3 Instant.

Quick Verdict

Pick GPT-5.3 Instant if you want the stronger benchmark profile. Nemotron 3 Ultra 500B only becomes the better choice if you need the larger 10M context window.

Agentic

GPT-5.3 Instant

GPT-5.3 Instant

82.9

Nemotron 3 Ultra 500B

62.8

86
Terminal-Bench 2.0
63
82
BrowseComp
69
80
OSWorld-Verified
58

Coding

GPT-5.3 Instant

GPT-5.3 Instant

78.7

Nemotron 3 Ultra 500B

43.8

88
HumanEval
66
76
SWE-bench Verified
42
75
LiveCodeBench
41
83
SWE-bench Pro
47

Multimodal & Grounded

GPT-5.3 Instant

GPT-5.3 Instant

95

Nemotron 3 Ultra 500B

66.9

95
MMMU-Pro
61
95
OfficeQA Pro
74

Reasoning

GPT-5.3 Instant

GPT-5.3 Instant

94.2

Nemotron 3 Ultra 500B

77.2

96
SimpleQA
71
94
MuSR
69
97
BBH
85
92
LongBench v2
81
94
MRCRv2
85

Knowledge

GPT-5.3 Instant

GPT-5.3 Instant

80.8

Nemotron 3 Ultra 500B

57

99
MMLU
74
98
GPQA
73
96
SuperGPQA
71
94
OpenBookQA
69
89
MMLU-Pro
73
44
HLE
15
92
FrontierScience
67

Instruction Following

GPT-5.3 Instant

GPT-5.3 Instant

96

Nemotron 3 Ultra 500B

84

96
IFEval
84

Multilingual

GPT-5.3 Instant

GPT-5.3 Instant

93.4

Nemotron 3 Ultra 500B

79.7

96
MGSM
81
92
MMLU-ProX
79

Mathematics

GPT-5.3 Instant

GPT-5.3 Instant

97.2

Nemotron 3 Ultra 500B

78

99
AIME 2023
74
99
AIME 2024
76
98
AIME 2025
75
95
HMMT Feb 2023
70
97
HMMT Feb 2024
72
96
HMMT Feb 2025
71
96
BRUMO 2025
73
98
MATH-500
84

Frequently Asked Questions

Which is better, GPT-5.3 Instant or Nemotron 3 Ultra 500B?

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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for knowledge tasks in this comparison, averaging 80.8 versus 57. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3 Instant or Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for coding in this comparison, averaging 78.7 versus 43.8. 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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for math in this comparison, averaging 97.2 versus 78. 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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for reasoning in this comparison, averaging 94.2 versus 77.2. 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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for agentic tasks in this comparison, averaging 82.9 versus 62.8. 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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for multimodal and grounded tasks in this comparison, averaging 95 versus 66.9. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3 Instant or Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for instruction following in this comparison, averaging 96 versus 84. 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 Nemotron 3 Ultra 500B?

GPT-5.3 Instant has the edge for multilingual tasks in this comparison, averaging 93.4 versus 79.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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