CustomGPT.ai vs ChatGPT: Answers for Visitors or for Colleagues

The short answer: you are not misreading the search results: CustomGPT.ai is its own company, not OpenAI's custom GPTs, even though its homepage title reads "Custom GPTs from Your Content for Business" (CustomGPT.ai). If the people asking are visitors on your website, CustomGPT.ai fits: Standard costs $99 a month on monthly billing for 1,000 queries, with a source linked under every answer (CustomGPT.ai pricing). If the people asking are your colleagues, ChatGPT Business fits: a Standard seat costs $25 a month on monthly billing, or $20 billed annually, for teams of 2 to 200 (OpenAI business pricing). Both checked on 26 October 2026. And the old answer, build a custom GPT, has an end date: OpenAI plans to retire custom GPTs in favour of Plugins (OpenAI help).

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Who is asking, in numbers:

1. Messages a month, and seats. For example, a site with 1,800 visitor messages a month outgrows Standard's 1,000: the 2,500-query add-on brings it to $99 + $375 = $474, while Premium at $499 includes 5,000 queries and auto-sync (CustomGPT.ai pricing). For nine colleagues, ChatGPT Business is 9 x $25 = $225 a month on monthly billing (OpenAI business pricing).
2. The ChatGPT plan you already pay for. Plus is $20 a month, billed monthly only (Plus article), and personal accounts on Free, Go, Plus or Pro can no longer create or publish new GPTs; existing ones keep working (OpenAI help). For CustomGPT.ai, the starting asset is your sitemap and the PDFs you already send to customers.
3. The record you will read. CustomGPT.ai keeps 7 days of analytics history on Standard and the full history on Premium (plan table). On Standard, read the questions it failed every week, or the evidence is gone.

The same job, two products

Read on 26 October 2026 from CustomGPT.ai's pricing page and FAQ and homepage, and OpenAI's business pricing, GPT creation article and GPT sharing article.

Three things that separate them

Outside the company, or inside it

A GPT lives in ChatGPT. Its sharing levels run from invite-only to the workspace, anyone with the link and the GPT Store, and each of those is a page inside ChatGPT (sharing article). CustomGPT.ai ships widgets that embed in your own site (homepage). A visitor comparing your plans at 23:00 will not log in to ChatGPT to ask. A sales rep checking a clause in the contract template already has. An agent that talks to visitors falls under Article 50 of the EU AI Act; the store support use case covers what its first message must say.

Grounded by design, or by instruction

CustomGPT.ai answers from the content you load and links each answer to its source (pricing page). OpenAI's guidance for a GPT says that if you want it to cite or quote uploaded files, say so in the instructions, and test in Preview (GPT creation article). One is a product built around citations; the other is a general assistant you can ask to behave like one.

A product with a price list, or a feature with a retirement date

For Enterprise workspaces, custom GPTs are planned to retire on 11 December 2026, other plans are expected to follow, and OpenAI recommends moving workflows to Plugins (GPT creation article). If you are about to build the company's answer bot as a GPT, you would be building it twice.

Prices on 26 October 2026

CustomGPT.ai (pricing page): Standard $99 a month billed monthly or $89 billed annually, for 10 agents, 1,000 queries and 3 team members; Premium $499 or $449, for 25 agents, 5,000 queries, 5 members and auto-sync; Enterprise custom. Extra queries cost $375 a month for 2,500. Every plan opens with a 7-day trial that takes a card and charges the chosen plan when it ends.

ChatGPT (business pricing, Plus article): Plus $20 a month, monthly only; Business Standard seat $25 monthly or $20 annually; Premium seat $125 monthly or $100 annually, with five times the usage of a standard seat; Enterprise custom.

One agent step: the website agent, inside ChatGPT

The two can share one knowledge base. Every CustomGPT.ai agent gets its own hosted MCP server at no cost (MCP overview); copy its token from Project, Deploy, MCP Server (deploy to ChatGPT). In a ChatGPT Business workspace, an admin or owner opens Plugins, chooses Add custom MCP server, enters the endpoint, accepts the risk warning and creates it as a plugin (OpenAI MCP article). CustomGPT.ai's guide still names the older Settings and Connectors route, so follow OpenAI's for the clicks. The connection can only send messages and read the agent's documents, by CustomGPT.ai's own setting. The human check comes before Publish: the admin @-mentions the plugin in a new chat, asks twenty real questions from sales and support, and opens every cited source. Only then does it reach the workspace. Each question is an interaction with the agent, and the pricing FAQ says every interaction consumes query credits.

Choose CustomGPT.ai if your job is

• Answering website visitors from your own pages, with a source under each answer.
• Putting one cited knowledge base on the site, in Slack and behind an API.
• Building without code, with a small team and a monthly price.

Choose ChatGPT if your job is

• Giving colleagues a general assistant for drafting, analysis and research.
• Working inside one workspace with connected apps, Plugins and admin controls.
• Paying per seat for unlimited use rather than per query.

The CustomGPT.ai entry covers its limits and plans. ChatGPT has no entry here; see chatgpt.com and OpenAI's business pricing.

The free test, then the query wall

Write down the 25 questions your inbox received most last month, with the page that answers each. Ask them of ChatGPT with those pages attached, then of a CustomGPT.ai agent in its trial week, and mark each answer right, wrong or unsourced. That sheet costs nothing and decides most cases.

When the month's queries run out, CustomGPT.ai's agents stop answering new questions on your live site, and the fix it sells is 2,500 more for $375 a month (pricing FAQ). Queries are counted across the account, so a test agent your team plays with draws on the same pool as the public one. Watch the usage page from week three and keep test agents for the trial.

FAQ

Is CustomGPT.ai part of OpenAI?

Neither vendor's pages present them as one company: CustomGPT.ai's site carries its own copyright line, and its plan table lists the OpenAI API, and on Enterprise Azure OpenAI and Claude through AWS Bedrock, as models it runs on (CustomGPT.ai pricing).

Can I still make a custom GPT on ChatGPT Plus?

No new ones. Personal accounts on Free, Go, Plus and Pro cannot create or publish new GPTs; GPTs you made earlier stay usable and editable if your plan allows (GPT creation article).

Can a GPT answer visitors on my website?

OpenAI's sharing options are invite-only, your workspace, anyone with the link and the GPT Store, all inside ChatGPT (sharing article). None of them is a widget for your own site.