Model Comparison

Llama 3.1 Nemotron Ultra 253B v1 vs LongCat-Flash-ChatWhich is better in 2026?

Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.

Verdict: Llama 3.1 Nemotron Ultra 253B v1 vs LongCat-Flash-Chat — which is better?

Llama 3.1 Nemotron Ultra 253B v1 (by NVIDIA) and LongCat-Flash-Chat (by Meituan) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Llama 3.1 Nemotron Ultra 253B v1 outperforms in 4 benchmarks (AIME 2025, GPQA, LiveCodeBench, MATH-500), while LongCat-Flash-Chat is better at 1 benchmark (IFEval). Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.

Choose Llama 3.1 Nemotron Ultra 253B v1 if…

  • you want the strongest raw capability — it leads on 4 of 5 shared benchmarks

Choose LongCat-Flash-Chat if…

  • you want the most recent training data — it shipped Aug 2025

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Llama 3.1 Nemotron Ultra 253B v1 outperforms in 4 benchmarks (AIME 2025, GPQA, LiveCodeBench, MATH-500), while LongCat-Flash-Chat is better at 1 benchmark (IFEval).

Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.

Mon Jul 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Model Size

Parameter count comparison

307.0B diff

LongCat-Flash-Chat has 307.0B more parameters than Llama 3.1 Nemotron Ultra 253B v1, making it 121.3% larger.

NVIDIA
Llama 3.1 Nemotron Ultra 253B v1
253.0Bparameters
Meituan
LongCat-Flash-Chat
560.0Bparameters
253.0B
Llama 3.1 Nemotron Ultra 253B v1
560.0B
LongCat-Flash-Chat

Context Window

Maximum input and output token capacity

Only LongCat-Flash-Chat specifies input context (128,000 tokens). Only LongCat-Flash-Chat specifies output context (128,000 tokens).

NVIDIA
Llama 3.1 Nemotron Ultra 253B v1
Input- tokens
Output- tokens
Meituan
LongCat-Flash-Chat
Input128,000 tokens
Output128,000 tokens
Mon Jul 27 2026 • llm-stats.com

License

Usage and distribution terms

Llama 3.1 Nemotron Ultra 253B v1 is licensed under Llama 3.1 Community License, while LongCat-Flash-Chat uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Llama 3.1 Nemotron Ultra 253B v1

Llama 3.1 Community License

Open weights

LongCat-Flash-Chat

MIT

Open weights

Release Timeline

When each model was launched

Llama 3.1 Nemotron Ultra 253B v1 was released on 2025-04-07, while LongCat-Flash-Chat was released on 2025-08-29.

LongCat-Flash-Chat is 5 months newer than Llama 3.1 Nemotron Ultra 253B v1.

Llama 3.1 Nemotron Ultra 253B v1

Apr 7, 2025

1.3 years ago

LongCat-Flash-Chat

Aug 29, 2025

11 months ago

4mo newer

Knowledge Cutoff

When training data ends

Llama 3.1 Nemotron Ultra 253B v1 has a documented knowledge cutoff of 2023-12-01, while LongCat-Flash-Chat's cutoff date is not specified.

We can confirm Llama 3.1 Nemotron Ultra 253B v1's training data extends to 2023-12-01, but cannot make a direct comparison without LongCat-Flash-Chat's cutoff date.

Llama 3.1 Nemotron Ultra 253B v1

Dec 2023

LongCat-Flash-Chat

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Outputs Comparison

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Key Takeaways

NVIDIA
Higher AIME 2025 score (72.5% vs 61.3%)
Higher GPQA score (76.0% vs 73.2%)
Higher LiveCodeBench score (66.3% vs 48.0%)
Higher MATH-500 score (97.0% vs 96.4%)
Meituan
Larger context window (128,000 tokens)
Higher IFEval score (89.6% vs 89.5%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat side-by-side, then vote on the output you prefer.

Llama 3.1 Nemotron Ultra 253B v1
✓ Preferred
LongCat-Flash-Chat
Open in Playground
AI Model Comparison Table
Feature
NVIDIA
Llama 3.1 Nemotron Ultra 253B v1
Meituan
LongCat-Flash-Chat

FAQ

Common questions about Llama 3.1 Nemotron Ultra 253B v1 vs LongCat-Flash-Chat.

Which is better, Llama 3.1 Nemotron Ultra 253B v1 or LongCat-Flash-Chat?

Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks. Llama 3.1 Nemotron Ultra 253B v1 is made by NVIDIA and LongCat-Flash-Chat is made by Meituan. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Llama 3.1 Nemotron Ultra 253B v1 compare to LongCat-Flash-Chat in benchmarks?

Llama 3.1 Nemotron Ultra 253B v1 scores MATH-500: 97.0%, IFEval: 89.5%, GPQA: 76.0%, BFCL v2: 74.1%, AIME 2025: 72.5%. LongCat-Flash-Chat scores MATH-500: 96.4%, MMLU: 89.7%, IFEval: 89.6%, ZebraLogic: 89.3%, HumanEval: 88.4%.

What are the context window sizes for Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat?

Llama 3.1 Nemotron Ultra 253B v1 supports an unknown number of tokens and LongCat-Flash-Chat supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat?

Key differences include licensing (Llama 3.1 Community License vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat?

Llama 3.1 Nemotron Ultra 253B v1 is developed by NVIDIA and LongCat-Flash-Chat is developed by Meituan.

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