This comparison is part of our MCP comparisons, within The MCP Guide. Facts are checked against each vendor's own documentation and pricing pages on the date shown.
If your company runs on ChatGPT Business or Enterprise, ChatGPT is the more direct route: admins add an MCP server as a plugin, test it and publish it to the workspace. If you run on Google Cloud, Gemini Enterprise connects MCP servers as admin-managed data stores with tight network controls. For individuals, the rules split sharply: Gemini's consumer app accepts custom MCP servers only for eligible US personal accounts, and ChatGPT limits custom servers to Pro (read/fetch) and business plans.
MCP (Model Context Protocol) is the open standard that lets an AI app call outside tools through "servers." Both OpenAI and Google back it through the Agentic AI Foundation.
Checked against: OpenAI's custom MCP server guide, Google's Gemini custom apps help page and Gemini Enterprise custom MCP docs on 28 October 2026. eSEOspace did not test either product.
Key Takeaways
- OpenAI says custom MCP connections with full MCP support are for ChatGPT Business and Enterprise/Edu on the web; Pro users can connect custom servers with read/fetch permissions only.
- Google's consumer Gemini app lets you add a "custom app" by MCP server URL if you are 18 or over, in the US, on a personal Google Account, with Keep Activity on.
- Gemini Enterprise connects MCP servers as a "custom MCP data store," set up by an admin in the Google Cloud console, Streamable HTTP only.
- ChatGPT reaches private servers through Secure MCP Tunnel; Gemini Enterprise routes private traffic through Agent Gateway.
- Both require confirmation before write actions by default, and both warn that they do not control third-party servers.
At a glance
| Item | ChatGPT | Gemini |
|---|---|---|
| Consumer custom MCP | Pro: read/fetch only; Free, Go, Plus not listed | Gemini app "custom apps": US, 18+, personal accounts, English |
| Business custom MCP | Business, Enterprise/Edu | Gemini Enterprise custom MCP data store |
| Where you add it | Plugins > + > Add custom MCP server | Consumer: Gemini web app; business: Google Cloud console |
| Transport | Public HTTPS MCP endpoint URL | Enterprise: Streamable HTTP only, SSE not supported |
| Private servers | Secure MCP Tunnel | Agent Gateway egress (Enterprise) |
| Mobile | Custom servers web only | Connect on web, then use on web and mobile |
| Tool limit | Not documented | Enterprise: up to 100 enabled actions at a time |
| Developer clients | Codex and ChatGPT desktop app | Antigravity app, IDE and CLI |
Where ChatGPT is stronger
Custom servers for business teams without cloud setup
In ChatGPT, an admin goes to Plugins, selects Add custom MCP server, enters a public HTTPS URL or a tunnel, sets up sign-in and selects Create as a plugin. OpenAI's help article says you "don't need to turn on Developer Mode first." There is no cloud project, IAM role or org policy to change, which suits small companies.
A test-then-publish workflow
OpenAI lets admins, owners and, on Enterprise/Edu, authorized developers "connect and test MCP servers privately before publishing" them for the workspace. Only admins and owners publish. After publishing, ChatGPT uses a "frozen" snapshot of the tools, so later server changes wait for an admin to publish an update.
Simpler path to private servers
Secure MCP Tunnel connects a server on a private network or developer machine "without exposing them publicly," per OpenAI. That is a single option inside the add-server dialog.
Developer clients share one config
OpenAI's ChatGPT and Codex MCP page says the ChatGPT desktop app, Codex CLI and IDE extension share MCP configuration and support local stdio and Streamable HTTP servers.
Where Gemini is stronger
Consumer access without a business plan
Google's help page says eligible users can add a custom app with its MCP server URL in the Gemini web app, then use it "in both the Gemini mobile app and Gemini web app." The page lists eligibility rules but no paid plan requirement. ChatGPT, by contrast, does not list Free, Go or Plus for custom servers.
Enterprise network and identity controls
Gemini Enterprise is built for Google Cloud admins. Creating the data store needs the Discovery Engine Editor role. Admins must override an org policy that blocks custom MCP data stores and allow the server's domain names. Private servers can sit inside a VPC (virtual private cloud), with traffic routed through Agent Gateway. Gemini Enterprise registers as an OAuth client with your identity provider, such as Okta, Azure AD or Google.
Actions off by default
When you connect a server to Gemini Enterprise, "all actions are turned off" by default. An admin turns on the ones people need, up to 100 at a time. That is a least-privilege default our MCP excessive permissions guide recommends.
A built-in MCP Store for developers
Google Antigravity's MCP docs describe an MCP Store, "a searchable list of available MCP servers," and one mcp_config.json shared by the Antigravity app, IDE and CLI. Local servers use stdio; remote servers use Streamable HTTP.
Pricing
Neither vendor charges separately for MCP. You pay for the plan.
| Tier | ChatGPT (chatgpt.com/pricing) | Gemini (gemini.google/subscriptions) |
|---|---|---|
| Free | $0; custom MCP not listed | $0; custom apps if eligible |
| Low tier | Go $8/month; custom MCP not listed | Google AI Plus $4.99/month |
| Main paid tier | Plus $20/month; custom MCP not listed in OpenAI's help | Google AI Pro $19.99/month |
| Top consumer tier | Pro from $100/month; read/fetch custom servers | Google AI Ultra from $99.99/month |
| Business | Business: price not shown on pages we opened | Gemini Enterprise Business edition from $21/seat/month |
| Enterprise | Contact sales | Standard/Plus editions from $30/seat/month |
ChatGPT's pricing table lists "Developer mode (beta)" on Plus and Pro, while OpenAI's help article, updated this week, lists custom MCP for Business, Enterprise/Edu and Pro (read/fetch). Check your own plan before relying on either.
Security and admin controls
| Control | ChatGPT | Gemini |
|---|---|---|
| Vendor warning | "Only connect servers you trust" | "Google does not control, monitor, or secure third-party MCP servers" |
| Write actions | Require confirmation by default, per OpenAI's developer guide | Consumer app "requires manual confirmation for any write actions" |
| Who adds servers (business) | Admins and owners; RBAC developers on Enterprise/Edu | Admins with Discovery Engine Editor role |
| Tool scoping | Admins publish a vetted snapshot | Actions off by default; enable up to 100 |
| Network | Public HTTPS or Secure MCP Tunnel | Public CA certificate, or Agent Gateway for private servers |
Google adds a candid note for consumers: Gemini "may share information from your chat and other available sources" with a custom app. OpenAI's developer guide says tools without a readOnlyHint annotation "are treated as write actions." Either way, start with read-only tools. Our MCP security risks guide covers the rest.
Which to choose
- Pick ChatGPT if your company already pays for ChatGPT Business or Enterprise and wants admins to add servers without cloud setup.
- Pick ChatGPT if your server runs on a private network and a tunnel is easier than VPC routing.
- Pick Gemini if you are a US individual on a personal Google Account and want to try a custom MCP server without a business plan.
- Pick Gemini Enterprise if your IT team runs Google Cloud and wants org policies, VPC routing and actions off by default.
- Pick by your developers' tools if the main users are engineers: Codex for OpenAI shops, Antigravity for Google shops.
For background on each company, read our spotlights on OpenAI and MCP and Google and MCP. More matchups are in our MCP comparisons.
Next step
Choose the app your staff already signs in to every day, then connect one read-only server as a pilot. If you are weighing a custom server that needs to work in ChatGPT, Gemini and Claude, talk to us about MCP development, or start with an MCP readiness audit.
Frequently asked questions
Can I add an MCP server to the free Gemini app?
Google's help page lists eligibility rules, not a paid plan: 18 or over, in the US, a personal Google Account, Keep Activity on, and English only. Work and school accounts are not supported for now.
Can I add an MCP server on ChatGPT Plus?
OpenAI's custom MCP article lists Business and Enterprise/Edu for full MCP and Pro for read/fetch. It does not list Plus. The pricing page shows "Developer mode (beta)" on Plus, so check your settings.
Does Gemini Enterprise support SSE MCP servers?
No. Google's docs say the older SSE transport isn't supported and the connector "exclusively supports the newer StreamableHTTP transport."
Which one can reach a server inside my network?
Both, with setup. ChatGPT uses Secure MCP Tunnel. Gemini Enterprise routes traffic through Agent Gateway into your VPC, supported in specific Google Cloud regions.
