Compare AI models

Specifications
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view.
1M—
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$0.22
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$0.66
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$0.007
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$0.0111Relace
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$0.18DeepInfra
$4,500Anthropic list price$21.00DeepInfra · fp8
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%39%
Humanity's Last Exam · with toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better.
65.6%34.8%
ARC-AGI-2Abstract reasoning — Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better.
90%61.4%
AutomationBenchBusiness workflows — Tests whether the AI can run real multi-step business workflows — the kind of end-to-end office processes companies want to automate — from start to finish. Higher is better.
31.4%25.1%
Overview
CompanyAnthropicDeepSeek
Release dateSep 1 2026Jul 31 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads DeepSeek-V4-Flash-0731 on 4 of the 4 benchmarks they both report (BullshitBench v2, Humanity's Last Exam, ARC-AGI-2, AutomationBench). DeepSeek-V4-Flash-0731 is cheaper on both input and output: $0.22 vs $10.00 per million input tokens, and $0.66 vs $50.00 per million output tokens. Figures are base-tier rates. DeepSeek-V4-Flash-0731 shipped 32 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Claude Fable 5.1 is closed, while DeepSeek-V4-Flash-0731 is open weight.

On BullshitBench v2, Claude Fable 5.1 leads at 77% vs DeepSeek-V4-Flash-0731 at 39%. On Humanity's Last Exam · with tools, Claude Fable 5.1 leads at 65.6% vs DeepSeek-V4-Flash-0731 at 34.8%. On ARC-AGI-2, Claude Fable 5.1 leads at 90% vs DeepSeek-V4-Flash-0731 at 61.4%. On AutomationBench, Claude Fable 5.1 leads at 31.4% vs DeepSeek-V4-Flash-0731 at 25.1%.