AnthropicClaude Fable 5VSxAIGrok 4.20
Our Take
We recommend Claude Fable 5 if you need peak intelligence for reasoning and coding tasks, or the 6.7x cheaper Grok 4.20 to optimize your budget for high-volume pipelines. While Claude Fable 5 holds a clear performance lead, it carries a heavy price premium. Choose Claude Fable 5 for complex logic, or Grok 4.20 for budget efficiency.
▶WHY?
Benchmark Calculations & Evidence:
Coding Benchmarks: Both models were evaluated on the SWE-bench Pro benchmark. Claude Fable 5 scored 80.3%, while Grok 4.20 scored 51.8%.
Reasoning Benchmarks: Both models were evaluated on the GPQA Diamond benchmark. Claude Fable 5 scored 94.1%, while Grok 4.20 scored 90%.
Cost Efficiency: Grok 4.20 pricing ($2/M input, $6/M output) is 6.7x cheaper than Claude Fable 5 ($10/M input, $50/M output).
Was this recommendation helpful?
Benchmarks & Scores
Coding (swe-bench-pro)Winner (+28.5%)
80.3%complex codebases, multi-file repositories, and architectural planning
Reasoning (gpqa-diamond)Winner (+4.1%)
94.1%graduate-level science QA
Cost & Context
Cost (per 1M tokens)
$20.00Input: $10.00 | Output: $50.00Context Window
1.05M tokensBenchmarks & Scores
Coding (swe-bench-pro)
51.8%complex codebases, multi-file repositories, and architectural planning
Reasoning (gpqa-diamond)
90%graduate-level science QA
Cost & Context
Cost (per 1M tokens)6.7x cheaper
$3.00Input: $2.00 | Output: $6.00Context Window
1.05M tokensFrequently Asked Questions about Claude Fable 5 vs Grok 4.20
Grok 4.20 is cheaper than Claude Fable 5. Grok 4.20 has a blended cost of $3.00/1M tokens, which is about 6.7x cheaper than Claude Fable 5 at $20.00/1M tokens.
Claude Fable 5 is better for coding tasks on this benchmark. It scores 80.3% on swe-bench-pro (complex codebases, multi-file repositories, and architectural planning) compared to Grok 4.20 which scores 51.8%.
Related Matchups
Explore similar comparisons for Claude Fable 5 and Grok 4.20.
Do you want to find a model for your constraints?
Use our interactive model finder to filter LLMs by reasoning capability, coding performance, cost, and context length.