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 | 128k |
| These models have no shared benchmark scores. | ||
Terminal-Bench 4.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Version 4.0 recalibrated how much time, CPU and memory each task gets, removed eight tasks and fixed nineteen, so fewer runs fail for reasons that have nothing to do with the model. Scores are not comparable with earlier versions. Higher is better. | 60.9% | — |
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Sep 1 2026 | Feb 12 2026 |
| Access | Closed | Closed |
| Model details | View model | View model |
Other comparisons
Claude Mythos 5.1vsGemini 4 ArgonGPT-5.3-Codex-SparkvsGemini 4 ArgonClaude Mythos 5.1vsMuse Spark OpenGPT-5.3-Codex-SparkvsMuse Spark OpenClaude Mythos 5.1vsGrok 4.7GPT-5.3-Codex-SparkvsGrok 4.7Claude Mythos 5.1vsDeepSeek-V4.1-FlashGPT-5.3-Codex-SparkvsDeepSeek-V4.1-FlashClaude Mythos 5.1vsMistral Large 4GPT-5.3-Codex-SparkvsMistral Large 4Claude Mythos 5.1vsKimi K3GPT-5.3-Codex-SparkvsKimi K3Frequently asked questions
Claude Mythos 5.1 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 201 days before Claude Mythos 5.1, so benchmark comparisons should account for the intervening progress.
Context windows are 1M (Claude Mythos 5.1) vs 128k (GPT-5.3-Codex-Spark).
Direct benchmark comparisons are unavailable — Claude Mythos 5.1 and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks.