ChatGPT vs Gemini Spark: Assistant or Always-On Agent?

Assistant You Visit vs Agent That Runs Without You

ChatGPT is the default AI assistant: you open it, ask, iterate and leave with an answer, and its agent mode can drive a browser through multi-step tasks during your session. Gemini Spark starts from the opposite end. It is an always-on agent that lives on Google Cloud VMs, keeps working with your devices off, and reports back: price tracking on a schedule, inbox triage with drafts waiting for approval, research digests that arrive without being asked twice.

Spark's other advantage is placement. It sits natively inside Gmail, Calendar, Drive, Docs and Sheets, so tasks that span your Google account need no setup at all, and custom MCP servers cover tools Google does not own. ChatGPT counters with breadth: a mature product available worldwide, an enormous plugin and GPT ecosystem, and years of refinement in how it reasons and writes.

Access and Price Decide This One for Most People

• ChatGPT has a genuinely useful free tier and a $20/mo Plus plan, available in most countries.
• Gemini Spark requires the $99.99/mo Google AI Ultra subscription, is a US-only beta, and carries undisclosed usage caps that even paying subscribers cannot raise. Early coverage also flagged unanswered privacy questions for an agent with this much account access.

Who Should Choose Which

Choose ChatGPT if you want the best general assistant for questions, writing, analysis and occasional agentic tasks at a reasonable price. Choose Gemini Spark only if your work already lives in Google Workspace, you are in the US, and recurring background automation is worth a hundred dollars a month to you. Spark points at where assistants are heading; ChatGPT is the better purchase for most people today.