The AI arena is free today

Open Superagent

Llama 3.1 Nemotron Ultra 253B v1 vs LongCat-Flash-Chat

Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat are closely matched at 19.1 and 19.8 on the LLM Stats Score.

NVIDIA · Meituan · Updated for 2026

Which is better?

Llama 3.1 Nemotron Ultra 253B v1 and LongCat-Flash-Chat are closely matched on the overall LLM Stats Score at 19.1 and 19.8.

In the 5 individual benchmarks reported for both models, Llama 3.1 Nemotron Ultra 253B v1 wins 4; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Llama 3.1 Nemotron Ultra 253B v1

  • you value its reported benchmark strengths — it wins 4 of 5 exact shared results

Choose LongCat-Flash-Chat

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

At a glance

The differences that matter most.

Llama 3.1 Nemotron Ultra 253B v1
NVIDIA
LongCat-Flash-Chat
Meituan
Core performance indexes
LLM Stats Score
19.1
#206
19.8
#198
Reasoning
18.8
#205
19.8
#194
Coding
12.4
#146
12.4
#146
Cost, coverage & limits
Benchmark wins
4 of 5
1 of 5
Input price
— / M
$0.30 / M
Output price
— / M
$1.20 / M
Context window
—
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Llama 3.1 Nemotron Ultra 253B v1
LongCat-Flash-Chat
Math
15.6#214
18.9#174
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

6 reported for Llama 3.1 Nemotron Ultra 253B v1 · 16 for LongCat-Flash-Chat

5 shared

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 Sep 21 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

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 Sep 21 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

1.5 years ago

LongCat-Flash-Chat

Aug 29, 2025

1.1 years 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

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

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

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 and LongCat-Flash-Chat are closely matched on the LLM Stats Score at 19.1 and 19.8. 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 capability indexes, individual benchmarks, pricing, and limits 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 LLM Stats Score (19.1 vs 19.8), 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.

Related comparisons