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.
1M200k
API pricingUSD per 1M tokens · lower wins
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$10.00$2.00
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$8.00
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$0.50
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$2.00OpenAI
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$8.00OpenAI
$4,500Anthropic list price$800OpenAI list price
Benchmarks
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
77%26%
Overview
CompanyAnthropicOpenAI
Release dateSep 1 2026Apr 16 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads o3 on 1 of the 1 benchmark they both report (BullshitBench v2). o3 is cheaper on both input and output: $2.00 vs $10.00 per million input tokens, and $8.00 vs $50.00 per million output tokens. o3 shipped 503 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Fable 5.1) vs 200k (o3).

On BullshitBench v2, Claude Fable 5.1 leads at 77% vs o3 at 26%.