256000
context tokens
Undisclosed
parameters
Proprietary
license
Jul 2025
released
// about Grok 4
xAI's 2025 flagship reasoning model
// similar models in Reasoning
Claude Fable 5
Anthropic's first Mythos-class model, tuned for the hardest coding benchmarks
Anthropic · Reasoning · Paid
GPT-5.6 Sol
OpenAI's flagship model for advanced math, science, and cybersecurity reasoning
OpenAI · Reasoning · Paid
Claude Opus 4.8
Anthropic's most capable Opus-tier model for deep analysis and long-horizon tasks
Anthropic · Reasoning · Paid
Claude Sonnet 4.5
Anthropic's most capable Sonnet-tier model at launch, tuned heavily for coding and computer use
Anthropic · Reasoning · Paid
DeepSeek V4-Pro
The top open-weight model of 2026, leading on agentic coding and graduate reasoning
DeepSeek · Reasoning · Free
GPT-5
OpenAI's unified reasoning and chat model family
OpenAI · Reasoning · Paid