One is where you try things; the other is where a company runs them. Google AI Studio is the free console for the Gemini API. Gemini Enterprise Agent Platform is what Vertex AI became on 23 April 2026, and it is where Google now puts everything enterprise: governance, scale, production.
Pick by who has to answer for the system, not by which is more powerful. The per-token cost of each is on the price comparison.
- AI Studio is free unless you link a paid API key.
- New accounts start on the Free Tier, with access to certain models up to their free limits.
- Paid means prepaying — Google asks for a minimum of $5 in credits.Google, Gemini API billing, read in a browser 16 Sep 2026: “prepaying to add a minimum of $5”.
- Agent Platform is the renamed Vertex AI, and Google says Vertex services now ship exclusively through it.
- On the free tier your prompts help improve Google products. On paid, Google says they do not.
Every price here was correct when this site last checked it, on 16 Sep 2026. Prices change often and this site no longer updates them, so check the vendor’s own page before you rely on one: Google pricing.
What is Google AI Studio?
The console you open to try a prompt, get an API key, and build something small. Google’s billing page is direct about the cost: “AI Studio usage remains free of charge unless users link a paid API key for access to paid features.” And on where everyone starts: “New accounts begin on the Free Tier, which allows access to certain models in the Gemini API and AI Studio, up to the models’ free tier rate limits.”Google, Gemini API billing, read in a browser 16 Sep 2026 (the docs refuse automated fetches).
Moving up is a deliberate act: a billing account, and money in it before you start.Google, Gemini API billing, read in a browser 16 Sep 2026: “Upgrading from the Free Tier to the Paid Tier means linking a billing account and prepaying to add a minimum of $5 (or equivalent in other currencies) of credits to your account.”
What is Gemini Enterprise Agent Platform?
Vertex AI, renamed and re-aimed. Google: “Today, we’re launching Gemini Enterprise Agent Platform — our new, comprehensive platform to build, scale, govern, and optimize agents.” The sentence that matters for planning is the next one: “Moving forward, all Vertex AI services and roadmap evolutions will be delivered exclusively through the Agent Platform, rather than as a standalone service.”Google Cloud, Introducing Gemini Enterprise Agent Platform, 23 Apr 2026, read at source 16 Sep 2026.
If your notes say Vertex AI, they are not wrong about the capability — only about the name and the door, which happened to most of Google’s line-up in 2026.
Which do you need?
| If this is you | Use |
|---|---|
| Trying a prompt, building a prototype, learning the API | AI Studio |
| One developer shipping a small app | AI Studio, paid key |
| A company that must govern, audit and scale agents | Agent Platform |
| Anyone whose plan says “Vertex AI” | Agent Platform |
If your plan says Vertex AI, check your Python imports too. On 18 September 2026 Google released version 2.0.1 of the Agent Platform SDK for Python, google-cloud-agentplatform, in a release-notes entry marked Breaking. Google says it “migrates generative AI modules to the Google Gen AI SDK, decouples the agent surface from google-cloud-aiplatform into a dedicated package, and introduces restructured namespaces.”Google Cloud, Agent Platform release notes, 18 Sep 2026, read in a browser 22 Sep 2026.
The difference nobody reads until later
Free and paid differ on more than rate limits. Google’s own pricing tables mark, for each model, whether inputs are “Used to improve our products” — Yes on the free tier, No on paid. If you are putting anything confidential through a free key, that line is the one to read first.Google, Gemini Developer API pricing, read in a browser 16 Sep 2026. The same distinction is described on the billing page as “Enterprise-grade data privacy” for paid tiers. The wider picture is on what happens to what you type.
What this page could not verify
- Whether old Vertex AI endpoints still answer. Google’s post does not say, and this page did not call them.
- Which models the free tier includes. Google says “certain models” without listing them there.
- Agent Platform pricing. Not covered in the announcement read here.
Google, Gemini API billing and pricing, read in a browser on 16 September 2026 · Google Cloud, Introducing Gemini Enterprise Agent Platform, 23 April 2026.
Pricing and tier rules change without notice. Re-read before committing.