The AI arena is free today

Open Superagent

Claude Mythos 5.2 vs Llama 3.1 Nemotron Ultra 253B v1

Claude Mythos 5.2 leads the LLM Stats Score 59.6 to 18.5.

Anthropic · NVIDIA · Updated for 2026

Which is better?

Claude Mythos 5.2 leads the overall LLM Stats Score 59.6 to 18.5, ranking #2 overall.

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

Choose Claude Mythos 5.2

  • overall performance matters — it scores 59.6 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you want the most recent training data — it shipped Nov 2026

Choose Llama 3.1 Nemotron Ultra 253B v1

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Mythos 5.2
Anthropic
Llama 3.1 Nemotron Ultra 253B v1
NVIDIA
Core performance indexes
LLM Stats Score
59.6
#2
18.5
#252
Reasoning
53.6
#7
18.2
#248
Coding
44.6
#5
12.3
#182
Cost, coverage & limits
Benchmark wins
—
—
Input price
$8.00 / M
— / M
Output price
$40.00 / M
— / M
Context window
1,000,000
—

Individual benchmarks

9 reported for Claude Mythos 5.2 · 6 for Llama 3.1 Nemotron Ultra 253B v1

No common benchmarks found

Claude Mythos 5.2 and Llama 3.1 Nemotron Ultra 253B v1don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Mythos 5.2 specifies input context (1,000,000 tokens). Only Claude Mythos 5.2 specifies output context (128,000 tokens).

Anthropic
Claude Mythos 5.2
Input1,000,000 tokens
Output128,000 tokens
NVIDIA
Llama 3.1 Nemotron Ultra 253B v1
Input- tokens
Output- tokens
Sat Nov 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Mythos 5.2 supports multimodal inputs, whereas Llama 3.1 Nemotron Ultra 253B v1 does not.

Claude Mythos 5.2 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Mythos 5.2

Text
Images
Audio
Video

Llama 3.1 Nemotron Ultra 253B v1

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Mythos 5.2 is licensed under a proprietary license, while Llama 3.1 Nemotron Ultra 253B v1 uses Llama 3.1 Community License.

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

Claude Mythos 5.2

Proprietary

Closed source

Llama 3.1 Nemotron Ultra 253B v1

Llama 3.1 Community License

Open weights

Release Timeline

When each model was launched

Claude Mythos 5.2 was released on 2026-11-09, while Llama 3.1 Nemotron Ultra 253B v1 was released on 2025-04-07.

Claude Mythos 5.2 is 19 months newer than Llama 3.1 Nemotron Ultra 253B v1.

Claude Mythos 5.2

Nov 9, 2026

4 days ago

1.6yr newer
Llama 3.1 Nemotron Ultra 253B v1

Apr 7, 2025

1.6 years ago

Knowledge Cutoff

When training data ends

Claude Mythos 5.2 has a knowledge cutoff of 2026-06-01, while Llama 3.1 Nemotron Ultra 253B v1 has a cutoff of 2023-12-01.

Claude Mythos 5.2 has more recent training data (up to 2026-06-01), making it potentially better informed about events through that date compared to Llama 3.1 Nemotron Ultra 253B v1 (2023-12-01).

Claude Mythos 5.2

Jun 2026

2.5 yr newer
Llama 3.1 Nemotron Ultra 253B v1

Dec 2023

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Mythos 5.2 and Llama 3.1 Nemotron Ultra 253B v1 side-by-side, then vote on the output you prefer.

Claude Mythos 5.2
✓ Preferred
Llama 3.1 Nemotron Ultra 253B v1
Open in Playground

FAQ

Common questions about Claude Mythos 5.2 vs Llama 3.1 Nemotron Ultra 253B v1.

Which is better, Claude Mythos 5.2 or Llama 3.1 Nemotron Ultra 253B v1?

Claude Mythos 5.2 leads the LLM Stats Score 59.6 to 18.5. Claude Mythos 5.2 is made by Anthropic and Llama 3.1 Nemotron Ultra 253B v1 is made by NVIDIA. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.2 compare to Llama 3.1 Nemotron Ultra 253B v1 in benchmarks?

Claude Mythos 5.2 scores De novo protein binder design: 85.1%, Biomedical image analysis: 80.7%, Protocols Troubleshooting: 77.1%, Terminal-Bench-Science 0.1: 75.3%, Terminal-Bench 4.0: 70.5%. 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%.

What are the context window sizes for Claude Mythos 5.2 and Llama 3.1 Nemotron Ultra 253B v1?

Claude Mythos 5.2 supports 1.0M tokens and Llama 3.1 Nemotron Ultra 253B v1 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos 5.2 and Llama 3.1 Nemotron Ultra 253B v1?

Key differences include LLM Stats Score (59.6 vs 18.5), multimodal support (yes vs no), licensing (Proprietary vs Llama 3.1 Community License). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.2 and Llama 3.1 Nemotron Ultra 253B v1?

Claude Mythos 5.2 is developed by Anthropic and Llama 3.1 Nemotron Ultra 253B v1 is developed by NVIDIA.

Related comparisons