ChatGPT (OpenAI) and Gemini (Google) are both top-tier assistants with very different strengths. Gemini is deeply tied to Google's search and workspace; ChatGPT has the broadest third-party ecosystem. Here is how to choose.
Gemini 3 is strong on factual, up-to-date answers (Google search grounding), long-context tasks, and multimodal input. ChatGPT (GPT-5.5) is a versatile all-rounder with excellent reasoning models and tooling. For research with live sources, Gemini and Perplexity are natural picks; for general assistance and coding, ChatGPT and Claude lead.
Gemini's Flash tier is fast and cheap; ChatGPT's mini models match it. Flagship vs flagship (GPT-5.5 vs Gemini 3 Pro), expect higher latency and cost for the deepest reasoning.
The honest answer is that it depends on your exact prompt — so the fastest way to decide is to run it through all of them at once. That is exactly what AISayWhat does: ask one question and see every model's answer side by side, with an automatic agreement analysis.
Gemini's search grounding helps with current, factual questions. For the most thorough sourced research, also compare Perplexity. AISayWhat lets you run all three at once.
Both are excellent; the difference is small for routine prompts. Compare them on a few of your real questions to see which voice and accuracy you prefer.
ChatGPT vs Claude — Which Should You Use?Claude vs Gemini — Which Should You Pick?What Is the Best AI for Coding?What Is the Best AI for Writing?