# GPT-5 GPT-5 is the fifth-generation [[Large Language Models (LLMs)|LLM]] family from [[OpenAI]]. It succeeds GPT-4 / GPT-4o as OpenAI's flagship closed-weight line and serves as the umbrella for the GPT-5.x minor releases that ship over a generation's lifetime. ## Variants Minor versions released / referenced as of May 2026: - **GPT-5** — initial generation release - **GPT-5.3** — interim refresh - **GPT-5.3-Codex** — coding-tuned 5.3 variant; long-time default for [[OpenAI Codex]] before 5.5 shipped - **[[GPT-5.4]]** — frontier flagship through April 2026; the version third parties (e.g., [[Moonshot AI]]'s K2.6 launch) used as their US closed-weight reference - **GPT-5.5** — current frontier; rolled into [[OpenAI Codex]] surfaces as the recommended default starting late April 2026 - **GPT-5.1-Codex-Mini** — lighter coding-tuned tier; the cost-control answer for routine Codex work that does not need 5.5 Specialty variants (mini / nano / turbo / pro / reasoning-tuned) follow OpenAI's usual tiering; check https://platform.openai.com/docs/models for the current list. ## Where each variant lives | Surface | Default model | |---|---| | ChatGPT (consumer) | GPT-5.5 | | [[OpenAI Codex]] (CLI / App / IDE / Cloud) | GPT-5.5 (was GPT-5.3-Codex through April 2026) | | OpenAI API | per-request; pick from the models endpoint | | Microsoft Azure / Foundry | enterprise tenants typically lag the consumer-side default | ## Positioning - Closed-weight, hosted via OpenAI API, ChatGPT, and Microsoft Azure / Foundry - Drives [[OpenAI Codex]] and agentic ChatGPT modes - Competes with [[Claude Opus 4.7]] ([[Anthropic]]), [[Gemini 3]] ([[Google DeepMind]]), and the open-weight frontier ([[Kimi K2.6]], [[Qwen]]) - The 2026 frontier race is effectively GPT-5.x vs Opus 4.x vs Gemini 3.x vs K2.x ## Why it matters - The default "current OpenAI model" that every other lab benchmarks against - ChatGPT's default model under the hood, which means GPT-5.x is what hundreds of millions of users touch daily, regardless of what the enterprise / API crowd prefers - Minor-version cadence (5.3 → 5.4 → …) is where the interesting quarterly deltas live; the "5 → 6" generational jump will be the larger story when it happens ## Caveats - OpenAI has not published full model cards at the minor-version level for every variant - Pricing, context window, and knowledge cutoff vary by surface (ChatGPT vs API vs Azure); check the live docs - Third-party comparison tables (e.g., in K2.6's launch) are directional, not authoritative ## References - OpenAI: https://openai.com/ - Model list: https://platform.openai.com/docs/models ## Related - [[OpenAI]] - [[GPT-5.4]] - [[GPT4]] - [[ChatGPT]] - [[OpenAI Codex]] - [[Large Language Models (LLMs)]] - [[AI Frontier Model]] - [[AI Foundation Models]] - [[Claude Opus 4.7]] - [[Gemini 3]] - [[Kimi K2.6]]