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.
1M—
Benchmarks
SWE-Bench ProAgentic coding — Can the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better.
77.8%54%
SWE-Bench MultilingualMultilingual coding — Like SWE-Bench, but the coding problems span many programming languages, not just one. Tests how broadly the AI can code. Higher is better.
87.3%79.8%
Terminal-Bench 2.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? (Version 2.0 of the test.) Higher is better.
82%69.3%
Overview
CompanyAnthropicSpaceXSI
Release dateApr 7 2026May 18 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Mythos Preview leads Composer 2.5 on 3 of the 3 benchmarks they both report (SWE-Bench Pro, SWE-Bench Multilingual, Terminal-Bench 2.0). Claude Mythos Preview shipped 41 days before Composer 2.5, 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 SWE-Bench Pro, Claude Mythos Preview leads at 77.8% vs Composer 2.5 at 54%. On SWE-Bench Multilingual, Claude Mythos Preview leads at 87.3% vs Composer 2.5 at 79.8%. On Terminal-Bench 2.0, Claude Mythos Preview leads at 82% vs Composer 2.5 at 69.3%.