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.
—$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.
—$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.
—$0.20
—$300SpaceXSI list price
Benchmarks
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.
93.9%70.8%
Overview
CompanyAnthropicSpaceXSI
Release dateApr 7 2026Aug 28 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Mythos Preview leads Grok Code Fast 1 on 1 of the 1 benchmark they both report (SWE-Bench Verified). Only Grok Code Fast 1 has a verified first-party price for an available API: $1.00 per million input tokens and $2.00 per million output tokens. No currently available pay-as-you-go API rate is tracked for Claude Mythos Preview. Grok Code Fast 1 shipped 222 days before Claude Mythos Preview, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Mythos Preview) vs 256k (Grok Code Fast 1).

On SWE-Bench Verified, Claude Mythos Preview leads at 93.9% vs Grok Code Fast 1 at 70.8%.