Nemotron Ultra 253B vs GPT-5 nano

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

Nemotron Ultra 253B is clearly ahead on the aggregate, 50 to 31. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5 nano gives you the larger context window at 400K, compared with 32K for Nemotron Ultra 253B.

Quick Verdict

Pick Nemotron Ultra 253B if you want the stronger benchmark profile. GPT-5 nano only becomes the better choice if mathematics is the priority or you need the larger 400K context window.

Knowledge

GPT-5 nano

Nemotron Ultra 253B

43.5

GPT-5 nano

71.2

49
MMLU
-
48
GPQA
71.2
46
SuperGPQA
-
44
OpenBookQA
-
63
MMLU-Pro
-
11
HLE
-

Coding

Nemotron Ultra 253B
41
HumanEval
-
31
SWE-bench Verified
-
30
LiveCodeBench
-

Mathematics

GPT-5 nano

Nemotron Ultra 253B

51.3

GPT-5 nano

85.2

49
AIME 2023
-
51
AIME 2024
-
50
AIME 2025
85.2
45
HMMT Feb 2023
-
47
HMMT Feb 2024
-
46
HMMT Feb 2025
-
48
BRUMO 2025
-
74
MATH-500
-

Reasoning

Nemotron Ultra 253B
47
SimpleQA
-
45
MuSR
-
77
BBH
-

Instruction Following

Nemotron Ultra 253B
78
IFEval
-

Multilingual

Nemotron Ultra 253B
74
MGSM
-

Frequently Asked Questions

Which is better, Nemotron Ultra 253B or GPT-5 nano?

Nemotron Ultra 253B is ahead overall, 50 to 31. The biggest single separator in this matchup is AIME 2025, where the scores are 50 and 85.2.

Which is better for knowledge tasks, Nemotron Ultra 253B or GPT-5 nano?

GPT-5 nano has the edge for knowledge tasks in this comparison, averaging 71.2 versus 43.5. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for math, Nemotron Ultra 253B or GPT-5 nano?

GPT-5 nano has the edge for math in this comparison, averaging 85.2 versus 51.3. Inside this category, AIME 2025 is the benchmark that creates the most daylight between them.

Last updated: March 9, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.