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Claude Mythos 5.1 vs Phi-3.5-vision-instruct

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to -3.4.

Anthropic · Microsoft · Updated for 2026

Which is better?

Claude Mythos 5.1 leads the overall LLM Stats Score 45.1 to -3.4, ranking #33 overall.

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

Choose Claude Mythos 5.1

  • overall performance matters — it scores 45.1 and ranks #33 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Phi-3.5-vision-instruct

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

At a glance

The differences that matter most.

Claude Mythos 5.1
Anthropic
Phi-3.5-vision-instruct
Microsoft
Core performance indexes
LLM Stats Score
45.1
#33
-3.4
#344
Reasoning
44.2
#37
-4.8
#344
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,000,000
—

Individual benchmarks

1 reported for Claude Mythos 5.1 · 9 for Phi-3.5-vision-instruct

No common benchmarks found

Claude Mythos 5.1 and Phi-3.5-vision-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 Mythos 5.1 specifies input context (1,000,000 tokens). Only Claude Mythos 5.1 specifies output context (128,000 tokens).

Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
Microsoft
Phi-3.5-vision-instruct
Input- tokens
Output- tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Mythos 5.1 and Phi-3.5-vision-instruct support multimodal inputs.

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

Claude Mythos 5.1

Text
Images
Audio
Video

Phi-3.5-vision-instruct

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Mythos 5.1 is licensed under a proprietary license, while Phi-3.5-vision-instruct uses MIT.

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

Claude Mythos 5.1

Proprietary

Closed source

Phi-3.5-vision-instruct

MIT

Open weights

Release Timeline

When each model was launched

Claude Mythos 5.1 was released on 2026-09-01, while Phi-3.5-vision-instruct was released on 2024-08-23.

Claude Mythos 5.1 is 25 months newer than Phi-3.5-vision-instruct.

Claude Mythos 5.1

Sep 1, 2026

2 weeks ago

2.0yr newer
Phi-3.5-vision-instruct

Aug 23, 2024

2.1 years ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Mythos 5.1 and Phi-3.5-vision-instruct side-by-side, then vote on the output you prefer.

Claude Mythos 5.1
✓ Preferred
Phi-3.5-vision-instruct
Open in Playground

FAQ

Common questions about Claude Mythos 5.1 vs Phi-3.5-vision-instruct.

Which is better, Claude Mythos 5.1 or Phi-3.5-vision-instruct?

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to -3.4. Claude Mythos 5.1 is made by Anthropic and Phi-3.5-vision-instruct is made by Microsoft. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.1 compare to Phi-3.5-vision-instruct in benchmarks?

Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%. Phi-3.5-vision-instruct scores ScienceQA: 91.3%, POPE: 86.1%, MMBench: 81.9%, ChartQA: 81.8%, AI2D: 78.1%.

What are the context window sizes for Claude Mythos 5.1 and Phi-3.5-vision-instruct?

Claude Mythos 5.1 supports 1.0M tokens and Phi-3.5-vision-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 Mythos 5.1 and Phi-3.5-vision-instruct?

Key differences include LLM Stats Score (45.1 vs -3.4), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.1 and Phi-3.5-vision-instruct?

Claude Mythos 5.1 is developed by Anthropic and Phi-3.5-vision-instruct is developed by Microsoft.

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