Claude Fable 5 (Anthropic) and Grok 4.6 (xAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 17 August 2026
As of 17 August 2026, Claude Fable 5 holds the stronger ModelCap Index position (#1 vs #10); Grok 4.6 is 8.3× cheaper per output token ($6.00/1M vs $50.00/1M); and Claude Fable 5 offers the longer context window (1M vs 500K tokens).
Evidence: 5 public benchmark observations across 5 boards · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Benchmark scores: Claude Fable 5 vs Grok 4.6
Public benchmark boards where Claude Fable 5 or Grok 4.6 has a published result
Claude Fable 5 ranks higher on the ModelCap Index as of 17 August 2026: #1 against #10. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.
Is Claude Fable 5 cheaper than Grok 4.6?
Grok 4.6 is cheaper on output tokens: $6.00/1M against $50.00/1M. Input tokens are $10.00/1M for Claude Fable 5 and $2.00/1M for Grok 4.6. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.
Which has the bigger context window, Claude Fable 5 or Grok 4.6?
Claude Fable 5 has the larger context window: 1M tokens against 500K.
Which is better for coding, Claude Fable 5 or Grok 4.6?
Arena coding: Claude Fable 5 1554, Grok 4.6 1512 — Claude Fable 5 leads.
Are Claude Fable 5 and Grok 4.6 open-weight models?
Claude Fable 5: API only. Grok 4.6: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
Where can I run Claude Fable 5 and Grok 4.6?
ModelCap currently lists 5 API providers for Claude Fable 5 and 1 for Grok 4.6, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
How current is this Claude Fable 5 vs Grok 4.6 comparison?
Every figure comes from the sealed ModelCap dataset published 17 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.