Compare AI models

Specifications
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
1M256k
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$10.00$1.00
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
$50.00$2.00
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
$0.25$0.20
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page.
$10.00Amazon Bedrock—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$50.00Amazon Bedrock—
$4,500Anthropic list price$300SpaceXSI list price
These models have no shared benchmark scores.
Overview
CompanyAnthropicSpaceXSI
Release dateSep 1 2026Aug 28 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 and Grok Code Fast 1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok Code Fast 1 is cheaper on both input and output: $1.00 vs $10.00 per million input tokens, and $2.00 vs $50.00 per million output tokens. Figures are base-tier rates. Grok Code Fast 1 shipped 369 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Fable 5.1) vs 256k (Grok Code Fast 1).

Direct benchmark comparisons are unavailable — Claude Fable 5.1 and Grok Code Fast 1 don't publish scores on any of the same benchmarks.