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.
1M128k
These models have no shared benchmark scores.
Overview
CompanyAnthropicOpenAI
Release dateApr 7 2026Feb 12 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Mythos Preview and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5.3-Codex-Spark shipped 54 days before Claude Mythos Preview, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Mythos Preview) vs 128k (GPT-5.3-Codex-Spark).

Direct benchmark comparisons are unavailable — Claude Mythos Preview and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks.