ChatGPT 5.1 vs Gemini 2.5: What Changed Today (Nov 12, 2025) — And Which AI Should You Use Now
Updated: November 12, 2025 TL;DR What’s new today (Nov 12, 2025) OpenAI: ChatGPT 5.1 launches. OpenAI introduced two refreshed models—GPT‑5.1 Instant and GPT‑5.1 Thinking—aimed at making replies feel more natural while improving reliability on both simple and complex tasks. OpenAI says Instant is warmer and better at following directions, while Thinking adapts how long it “thinks” based on task complexity. Rollout starts now for paid ChatGPT plans, with API access “later this week,” and GPT‑5 remains as a legacy option for three months. OpenAI also expanded built‑in tone/personalization controls. OpenAI Independent coverage confirms the new personality presets (Default, Professional, Friendly,