Claude Fable 5.2 vs Grok-4 Heavy
Claude Fable 5.2 leads the LLM Stats Score 61.3 to 40.1.
Anthropic · xAI · Updated for 2026
Which is better?
Claude Fable 5.2 leads the overall LLM Stats Score 61.3 to 40.1, ranking #1 overall.
In the 1 individual benchmarks reported for both models, Claude Fable 5.2 wins 1; this is a narrower head-to-head signal than the composite indexes.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Fable 5.2
- overall performance matters — it scores 61.3 and ranks #1 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
Choose Grok-4 Heavy
- you are already invested in the xAI ecosystem
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
29 reported for Claude Fable 5.2 · 6 for Grok-4 Heavy
Claude Fable 5.2 outperforms in 1 benchmarks (Humanity's Last Exam), while Grok-4 Heavy is better at 0 benchmarks.
Claude Fable 5.2 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Only Claude Fable 5.2 specifies input context (1,000,000 tokens). Only Claude Fable 5.2 specifies output context (128,000 tokens).
Input capabilities
Documented input modalities across available providers
Both Claude Fable 5.2 and Grok-4 Heavy support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Fable 5.2
Grok-4 Heavy
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Fable 5.2 was released on 2026-11-09, while Grok-4 Heavy's release date is not specified.
We can confirm Claude Fable 5.2's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.
Nov 9, 2026
0 days ago
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Knowledge Cutoff
When training data ends
Claude Fable 5.2 has a knowledge cutoff of 2026-06-01, while Grok-4 Heavy has a cutoff of 2024-12-31.
Claude Fable 5.2 has more recent training data (up to 2026-06-01), making it potentially better informed about events through that date compared to Grok-4 Heavy (2024-12-31).
Jun 2026
1.5 yr newerDec 2024
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Fable 5.2 and Grok-4 Heavy side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Fable 5.2 vs Grok-4 Heavy.