The AI arena is free today

Open Superagent

Claude Opus 5.5 vs Mistral Small 3.1 24B Instruct

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 4.2.

Anthropic · Mistral AI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 59.7 to 4.2, ranking #1 overall.

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

Choose Claude Opus 5.5

  • overall performance matters — it scores 59.7 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Mistral Small 3.1 24B Instruct

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

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Mistral Small 3.1 24B Instruct
Mistral AI
Core performance indexes
LLM Stats Score
59.7
#1
4.2
#309
Reasoning
57.8
#1
4.2
#302
Coding
51.7
#1
9.7
#176
Cost, coverage & limits
Benchmark wins
—
—
Input price
$4.00 / M
— / M
Output price
$20.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
Mistral Small 3.1 24B Instruct
Math
42.5#5
7.9#262
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 9 for Mistral Small 3.1 24B Instruct

No common benchmarks found

Claude Opus 5.5 and Mistral Small 3.1 24B Instructdon'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 Opus 5.5 specifies input context (1,000,000 tokens). Only Claude Opus 5.5 specifies output context (128,000 tokens).

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Mistral AI
Mistral Small 3.1 24B Instruct
Input- tokens
Output- tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and Mistral Small 3.1 24B Instruct support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 5.5

Text
Images
Audio
Video

Mistral Small 3.1 24B Instruct

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5.5 is licensed under a proprietary license, while Mistral Small 3.1 24B Instruct uses Apache 2.0.

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

Claude Opus 5.5

Proprietary

Closed source

Mistral Small 3.1 24B Instruct

Apache 2.0

Open weights

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Mistral Small 3.1 24B Instruct was released on 2025-03-17.

Claude Opus 5.5 is 18 months newer than Mistral Small 3.1 24B Instruct.

Claude Opus 5.5

Sep 22, 2026

0 days ago

1.5yr newer
Mistral Small 3.1 24B Instruct

Mar 17, 2025

1.5 years ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while Mistral Small 3.1 24B Instruct's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Mistral Small 3.1 24B Instruct's cutoff date.

Claude Opus 5.5

Jun 2026

Mistral Small 3.1 24B Instruct

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Mistral Small 3.1 24B Instruct side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Mistral Small 3.1 24B Instruct
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Mistral Small 3.1 24B Instruct.

Which is better, Claude Opus 5.5 or Mistral Small 3.1 24B Instruct?

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 4.2. Claude Opus 5.5 is made by Anthropic and Mistral Small 3.1 24B Instruct is made by Mistral AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5.5 compare to Mistral Small 3.1 24B Instruct in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. Mistral Small 3.1 24B Instruct scores HumanEval: 88.4%, MMLU: 80.6%, TriviaQA: 80.5%, MBPP: 74.7%, MATH: 69.3%.

What are the context window sizes for Claude Opus 5.5 and Mistral Small 3.1 24B Instruct?

Claude Opus 5.5 supports 1.0M tokens and Mistral Small 3.1 24B Instruct 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 Opus 5.5 and Mistral Small 3.1 24B Instruct?

Key differences include LLM Stats Score (59.7 vs 4.2), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Mistral Small 3.1 24B Instruct?

Claude Opus 5.5 is developed by Anthropic and Mistral Small 3.1 24B Instruct is developed by Mistral AI.

Related comparisons