Frontier Model
8 milestones in AI history
Gemini: Google's Multimodal Response
Google launched Gemini, its most capable AI model family, natively multimodal across text, code, images, audio, and video. Gemini Ultra matched or exceeded GPT-4 on many benchmarks. It marked Google DeepMind's full response to OpenAI's dominance.
Claude 3: Approaching Human-Level
Anthropic launched the Claude 3 family (Haiku, Sonnet, Opus), with Claude 3 Opus matching or exceeding GPT-4 on most benchmarks. It featured a 200K token context window, strong reasoning, nuanced instruction-following, and a 'personality' that users found distinctively thoughtful and careful.
Claude 4 / Opus 4: Frontier Reasoning
Anthropic released Claude 4 Opus, a model with significantly enhanced reasoning, extended thinking capabilities, and the ability to sustain complex multi-step problem-solving over long contexts. It excelled at agentic tasks, code generation, and nuanced analysis.
OpenAI o3: Advanced Reasoning at Scale
OpenAI released o3, the successor to o1, with markedly improved reasoning capabilities. It posted state-of-the-art results on many math and coding benchmarks and handled problems that previously required expert-level multi-step analysis.
Claude 4.5 / 4.6 Opus: Frontier Agentic Capability
Anthropic released Claude 4.5 and 4.6 Opus, representing the frontier of AI capability in early 2026. These models demonstrated unprecedented reasoning depth, coding ability, and capacity for autonomous multi-step work. They could sustain complex agentic workflows, manage entire projects, and collaborate with other AI agents.
Claude Fable 5 and Mythos 5: A New Model Tier
Anthropic released Claude Fable 5 and Claude Mythos 5, the first models in the Claude 5 family and a new 'Mythos-class' tier positioned above Opus in capability. The two share the same underlying model: Fable 5 shipped for general availability with additional safeguards on dual-use capabilities, while Mythos 5 was restricted to approved organizations. The Mythos class had been introduced in April 2026 through Claude Mythos Preview, released via Project Glasswing to a limited set of cyberdefense and infrastructure organizations.
GPT-5.6 and ChatGPT Work
OpenAI released GPT-5.6 in three tiers — Sol at the top, mid-range Terra, and the fast, cheap Luna — alongside ChatGPT Work, an agent built to carry out whole jobs rather than just answer questions: operating across applications and files, running long tasks, and producing documents, spreadsheets, and websites. Three weeks later OpenAI cut Luna's price by 80% and Terra's by 20% as competitive pressure mounted.
Claude Opus 5: Frontier Capability at Half the Price
Anthropic released Claude Opus 5, approaching Claude Fable 5-level intelligence at roughly half the price. It introduced an 'effort' dial that let users trade off cost and capability per request, alongside stronger coding, agentic, and self-verification performance.