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Claude Fable 5.1 vs Grok-1.5V

Claude Fable 5.1 leads the LLM Stats Score 54.8 to -0.6.

Anthropic · xAI · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 54.8 to -0.6, ranking #5 overall.

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

Choose Claude Fable 5.1

  • overall performance matters — it scores 54.8 and ranks #5 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Grok-1.5V

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

Claude Fable 5.1
Anthropic
Grok-1.5V
xAI
Core performance indexes
LLM Stats Score
54.8
#5
-0.6
#316
Reasoning
52.1
#7
0.1
#303
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Fable 5.1
Grok-1.5V
Vision
40.5#1
-1.2#179
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for Claude Fable 5.1 · 7 for Grok-1.5V

No common benchmarks found

Claude Fable 5.1 and Grok-1.5Vdon'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 Fable 5.1 specifies input context (1,000,000 tokens). Only Claude Fable 5.1 specifies output context (128,000 tokens).

Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
xAI
Grok-1.5V
Input- tokens
Output- tokens
Wed Sep 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Fable 5.1 and Grok-1.5V support multimodal inputs.

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

Claude Fable 5.1

Text
Images
Audio
Video

Grok-1.5V

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Fable 5.1

Proprietary

Closed source

Grok-1.5V

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while Grok-1.5V was released on 2024-04-12.

Claude Fable 5.1 is 29 months newer than Grok-1.5V.

Claude Fable 5.1

Sep 1, 2026

1 days ago

2.4yr newer
Grok-1.5V

Apr 12, 2024

2.4 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 Fable 5.1 and Grok-1.5V side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
Grok-1.5V
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs Grok-1.5V.

Which is better, Claude Fable 5.1 or Grok-1.5V?

Claude Fable 5.1 leads the LLM Stats Score 54.8 to -0.6. Claude Fable 5.1 is made by Anthropic and Grok-1.5V is made by xAI. 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 Grok-1.5V 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%. Grok-1.5V scores AI2D: 88.3%, DocVQA: 85.6%, TextVQA: 78.1%, ChartQA: 76.1%, RealWorldQA: 68.7%.

What are the context window sizes for Claude Fable 5.1 and Grok-1.5V?

Claude Fable 5.1 supports 1.0M tokens and Grok-1.5V 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 Fable 5.1 and Grok-1.5V?

Key differences include LLM Stats Score (54.8 vs -0.6). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and Grok-1.5V?

Claude Fable 5.1 is developed by Anthropic and Grok-1.5V is developed by xAI.

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