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Claude Fable 5.1 vs Phi 4

Claude Fable 5.1 leads the LLM Stats Score 57.0 to 5.7. Phi 4 is 228.6x cheaper per token.

Anthropic · Microsoft · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 57.0 to 5.7, ranking #1 overall.

On price, Phi 4 is roughly 228.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Fable 5.1 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 Fable 5.1

  • overall performance matters — it scores 57.0 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — 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 Phi 4

  • cost matters — it's about 228.6x cheaper per token
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
57.0
#1
5.7
#284
54.5
#4
6.8
#274
37.0
#17
3.5
#208
Cost, coverage & limits
Benchmark wins
Input price
$10.00 / M
$0.07 / M
Output price
$50.00 / M
$0.14 / M
Context window
1,000,000
16,000

Individual benchmarks

7 reported for Claude Fable 5.1 · 13 for Phi 4

No common benchmarks found

Claude Fable 5.1 and Phi 4don'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

Phi 4 costs less

For input processing, Claude Fable 5.1 ($10.00/1M tokens) is 142.9x more expensive than Phi 4 ($0.07/1M tokens).

For output processing, Claude Fable 5.1 ($50.00/1M tokens) is 357.1x more expensive than Phi 4 ($0.14/1M tokens).

In conclusion, Claude Fable 5.1 is more expensive than Phi 4.*

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

Lowest available price from all providers
Thu Sep 03 2026 • llm-stats.com
Anthropic
Claude Fable 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Microsoft
Phi 4
Input tokens$0.07
Output tokens$0.14
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Claude Fable 5.1 accepts 1,000,000 input tokens compared to Phi 4's 16,000 tokens. Claude Fable 5.1 can generate longer responses up to 128,000 tokens, while Phi 4 is limited to 16,000 tokens.

Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Microsoft
Phi 4
Input16,000 tokens
Output16,000 tokens
Thu Sep 03 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Fable 5.1 supports multimodal inputs, whereas Phi 4 does not.

Claude Fable 5.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Fable 5.1

Text
Images
Audio
Video

Phi 4

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Fable 5.1 is licensed under a proprietary license, while Phi 4 uses MIT.

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

Claude Fable 5.1

Proprietary

Closed source

Phi 4

MIT

Open weights

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while Phi 4 was released on 2024-12-12.

Claude Fable 5.1 is 21 months newer than Phi 4.

Claude Fable 5.1

Sep 1, 2026

1 days ago

1.7yr newer
Phi 4

Dec 12, 2024

1.7 years ago

Knowledge Cutoff

When training data ends

Phi 4 has a documented knowledge cutoff of 2024-06-01, while Claude Fable 5.1's cutoff date is not specified.

We can confirm Phi 4's training data extends to 2024-06-01, but cannot make a direct comparison without Claude Fable 5.1's cutoff date.

Claude Fable 5.1

Phi 4

Jun 2024

Provider Availability

Claude Fable 5.1 is available from Anthropic. Phi 4 is available from DeepInfra.

Claude Fable 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

Phi 4

deepinfra logo
Deepinfra
Input Price:Input: $0.07/1MOutput Price:Output: $0.14/1M
* 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 Fable 5.1 and Phi 4 side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
Phi 4
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs Phi 4.

Which is better, Claude Fable 5.1 or Phi 4?

Claude Fable 5.1 leads the LLM Stats Score 57.0 to 5.7. Claude Fable 5.1 is made by Anthropic and Phi 4 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 Fable 5.1 compare to Phi 4 in benchmarks?

Claude Fable 5.1 scores OSWorld 2.0: 77.9%, CursorBench v3.2: 73.4%, Humanity's Last Exam: 65.0%, GDPval-AA: 61.8%, Terminal-Bench 4.0: 55.8%. Phi 4 scores MMLU: 84.8%, HumanEval+: 82.8%, HumanEval: 82.6%, MGSM: 80.6%, MATH: 80.4%.

Is Claude Fable 5.1 cheaper than Phi 4?

Phi 4 is 142.9x cheaper for input tokens. Claude Fable 5.1 costs $10.00/M input and $50.00/M output via anthropic. Phi 4 costs $0.07/M input and $0.14/M output via deepinfra.

What are the context window sizes for Claude Fable 5.1 and Phi 4?

Claude Fable 5.1 supports 1.0M tokens and Phi 4 supports 16K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Fable 5.1 and Phi 4?

Key differences include LLM Stats Score (57.0 vs 5.7), context window (1.0M vs 16K), input pricing ($10.00 vs $0.07/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and Phi 4?

Claude Fable 5.1 is developed by Anthropic and Phi 4 is developed by Microsoft.