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.
200k—
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.
—$1.25
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.
—$2.50
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.
—$0.20
—$375SpaceXSI 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.
34%56%
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better.
72.5%76.7%
Overview
CompanyAnthropicSpaceXSI
Release dateMay 22 2025Feb 17 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Grok 4.20 Beta leads Claude Opus 4 on 2 of the 2 benchmarks they both report (BullshitBench v2, SWE-Bench Verified). Only Grok 4.20 Beta has a verified first-party price for an available API: $1.25 per million input tokens and $2.50 per million output tokens. No currently available pay-as-you-go API rate is tracked for Claude Opus 4. Claude Opus 4 shipped 271 days before Grok 4.20 Beta, 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.

On BullshitBench v2, Grok 4.20 Beta leads at 56% vs Claude Opus 4 at 34%. On SWE-Bench Verified, Grok 4.20 Beta leads at 76.7% vs Claude Opus 4 at 72.5%.