Claude Fable 5.1 vs Grok 4.6

Grok 4.6 is cheaper at $2 per million input tokens, against $10 for Claude Fable 5.1 — roughly 5.0× the price. Estimate both input and output token volume for your workload. These are base rates; Claude Fable 5.1: Standard USD/MTok input/output $10/$50 with no long-context surcharge; cache reads $0.25 versus Fable 5's $1, 5-minute writes $12.50, 1-hour writes $20. Batch $5/$25. US-only inference adds 10% to input/output and cache reads/writes on Anthropic-operated routes where supported; Foundry uses US Data Zone Standard. Bedrock and Google-managed Google Cloud have independent regional prices. Adaptive thinking is always on; default effort high. Knowledge cutoff June 2026; retirement not sooner than September 1, 2027. Server-side tools can add usage fees; tool schemas/results and thinking consume billable tokens. Grok 4.6: Standard USD/MTok input/output $2/$6 below 200K prompt tokens; at 200K or more the full request bills $4/$12. Cached input $0.50/$1.00 for short/long requests. Batch discounts all token types by 20%; available regions and team access still apply. API Priority is 2x Standard for all token types and is billed only when the response confirms service_tier priority; it does not combine with Batch. US regional inference adds 10% to input/output/cache rates. Server tools have separate fees: web search/code execution/attachments $5 per 1,000 calls; X search $5 per 1,000 fetched posts or $10 per 1,000 profiles; collections search $2.50 per 1,000 calls. Search can fetch multiple billed items; reasoning and media tokens are also billable.

Grok 4.6 is cheaper at $6 per million output tokens, against $50 for Claude Fable 5.1 — roughly 8.3× the price. Estimate both input and output token volume for your workload. These are base rates; Claude Fable 5.1: Standard USD/MTok input/output $10/$50 with no long-context surcharge; cache reads $0.25 versus Fable 5's $1, 5-minute writes $12.50, 1-hour writes $20. Batch $5/$25. US-only inference adds 10% to input/output and cache reads/writes on Anthropic-operated routes where supported; Foundry uses US Data Zone Standard. Bedrock and Google-managed Google Cloud have independent regional prices. Adaptive thinking is always on; default effort high. Knowledge cutoff June 2026; retirement not sooner than September 1, 2027. Server-side tools can add usage fees; tool schemas/results and thinking consume billable tokens. Grok 4.6: Standard USD/MTok input/output $2/$6 below 200K prompt tokens; at 200K or more the full request bills $4/$12. Cached input $0.50/$1.00 for short/long requests. Batch discounts all token types by 20%; available regions and team access still apply. API Priority is 2x Standard for all token types and is billed only when the response confirms service_tier priority; it does not combine with Batch. US regional inference adds 10% to input/output/cache rates. Server tools have separate fees: web search/code execution/attachments $5 per 1,000 calls; X search $5 per 1,000 fetched posts or $10 per 1,000 profiles; collections search $2.50 per 1,000 calls. Search can fetch multiple billed items; reasoning and media tokens are also billable.

Claude Fable 5.1 accepts 1M tokens against 500K for Grok 4.6. This only matters if you routinely send very long documents or large codebases.

Claude Fable 5.1 exposes low, medium, high, xhigh, max, while Grok 4.6 exposes low, medium, high, xhigh.

Both are classified in our frontier tier; this editorial grouping does not imply equal capability. Claude Fable 5.1 is a candidate for frontier agents; Grok 4.6 is a candidate for coding agents. Compare accuracy, tool reliability, latency and cost on representative tasks.