The AI arena is free today

Open Superagent

Claude Opus 5.5 vs Mistral Small 3.1 24B Base

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 0.3. Mistral Small 3.1 24B Base is 53.3x cheaper per token.

Anthropic · Mistral AI · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 59.7 to 0.3, ranking #1 overall.

On price, Mistral Small 3.1 24B Base is roughly 53.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 5.5 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

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 — it leads those capability indexes
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose Mistral Small 3.1 24B Base

  • cost matters — it's about 53.3x cheaper per token
  • 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 Base
Mistral AI
Core performance indexes
LLM Stats Score
59.7
#1
0.3
#331
Reasoning
57.8
#1
0.5
#322
Cost, coverage & limits
Benchmark wins
—
—
Input price
$4.00 / M
$0.10 / M
Output price
$20.00 / M
$0.30 / M
Context window
1,000,000
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
Mistral Small 3.1 24B Base
Math
42.5#5
4.7#280
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 5 for Mistral Small 3.1 24B Base

No common benchmarks found

Claude Opus 5.5 and Mistral Small 3.1 24B Basedon'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

Pricing Analysis

Price comparison per million tokens

Mistral Small 3.1 24B Base costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 40.0x more expensive than Mistral Small 3.1 24B Base ($0.10/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 66.7x more expensive than Mistral Small 3.1 24B Base ($0.30/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than Mistral Small 3.1 24B Base.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Sep 22 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
Mistral AI
Mistral Small 3.1 24B Base
Input tokens$0.10
Output tokens$0.30
Best providerMistral
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 5.5 accepts 1,000,000 input tokens compared to Mistral Small 3.1 24B Base's 128,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Mistral AI
Mistral Small 3.1 24B Base
Input128,000 tokens
Output128,000 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 Base 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 Base

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 Base 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 Base

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 Base was released on 2025-03-17.

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

Claude Opus 5.5

Sep 22, 2026

0 days ago

1.5yr newer
Mistral Small 3.1 24B Base

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 Base'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 Base's cutoff date.

Claude Opus 5.5

Jun 2026

Mistral Small 3.1 24B Base

—

Provider Availability

Claude Opus 5.5 is available from Anthropic. Mistral Small 3.1 24B Base is available from Mistral AI.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

Mistral Small 3.1 24B Base

mistral logo
Mistral
Input Price:Input: $0.10/1MOutput Price:Output: $0.30/1M
* Prices shown are per million tokens

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 Base side-by-side, then vote on the output you prefer.

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

FAQ

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

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

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 0.3. Claude Opus 5.5 is made by Anthropic and Mistral Small 3.1 24B Base 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 Base 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 Base scores MMLU: 81.0%, TriviaQA: 80.5%, MMMU: 59.3%, MMLU-Pro: 56.0%, GPQA: 37.5%.

Is Claude Opus 5.5 cheaper than Mistral Small 3.1 24B Base?

Mistral Small 3.1 24B Base is 40.0x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Mistral Small 3.1 24B Base costs $0.10/M input and $0.30/M output via mistral.

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

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

Key differences include LLM Stats Score (59.7 vs 0.3), context window (1.0M vs 128K), input pricing ($4.00 vs $0.10/M), 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 Base?

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

Related comparisons