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Specifications
Context window
1M—
API pricing
Input price
$10.00—
Output price
$50.00—
Cached input price
$0.25—
Cheapest input
$10.00Amazon Bedrock—
Cheapest output
$50.00Amazon Bedrock—

These models have no shared benchmark scores.

Overview
CompanyAnthropicSpaceXAI
Release dateSep 1 2026Jul 9 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 and Grok 4 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only Claude Fable 5.1 has a verified first-party API price: $10.00 per million input tokens and $50.00 per million output tokens. No pay-as-you-go API rate is tracked for Grok 4. Grok 4 shipped 419 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude Fable 5.1 and Grok 4 don't publish scores on any of the same benchmarks.