Custom ChatGPT for Your Website: Embed Options as Custom GPTs Retire

Not as a custom GPT. Custom GPTs run inside ChatGPT rather than on your own pages, and OpenAI has scheduled them to retire on 11 December 2026. To put an assistant on your website, use a chatbot builder trained on your own pages (Chatbase, Botpress, Tidio and similar) or pay a developer to build on OpenAI's API.

"Trained on your pages" does not mean a model is retrained. Tools like these generally search your pages and uploads for the relevant passages and have an AI write the answer from them. Two things follow before you compare prices: the bot is only as accurate as your pages are current, and every vendor counts usage in a different unit, so the monthly price on the box tells you far less than the number of conversations you expect.

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What a custom GPT was, and what happens to it in December

A custom GPT is a saved bundle of instructions, uploaded files and optional actions that runs inside ChatGPT. You share it by link, and the person who opens the link uses it on chatgpt.com. It was designed for you, your staff or people who already use ChatGPT, not as a widget for a business website.

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OpenAI's retirement and migration FAQ says custom GPTs are scheduled to retire on 11 December 2026 and that the change affects all ChatGPT plans; Enterprise workspaces with an approved deferral get until 11 February 2027. Creating new ones has already ended for most accounts. Where a workspace can migrate, the GPT's instructions become a skill inside a plugin, its knowledge files are copied into the plugin as reference files and its connected apps come across as apps. Custom actions, the selected model, unpublished drafts and the GPT's public sharing settings do not, and the new plugin starts private, so people who used the GPT do not get access automatically. The original stays usable until retirement but becomes read-only once migrated. Plugins and skills are for Business and Enterprise workspaces; on a Plus plan the practical replacement is a ChatGPT Project.

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None of those replacements puts a chat on your website. Claude Projects and Gemini Gems (becoming skills from November 2026) share the same design: they are for you and your team inside the vendor's own app. For the staff-facing side of the move, moving each custom GPT to a Project, skill or plugin goes through the options. The rest of this tutorial is about the public-facing question.

Five ways to get an assistant in front of website visitors

1. Link out to a custom GPT. Free and fast, but visitors leave your site, and the link stops working when the GPT retires (scheduled for 11 December). Not worth building on now.
2. Your site builder's own assistant. Shopify's Inbox and Wix's Smart Chat both have one. No new subscription, though you are tied to that platform.
3. A chatbot builder trained on your pages and files. Chatbase, Botpress, Tidio, Wonderchat, CustomGPT.ai and others. You paste a short snippet into your site or install a plugin. This is where most small sites end up.
4. The AI agent inside a help desk you already run. Intercom's Fin, or HubSpot's Customer Agent. Sensible if the help desk exists for other reasons.
5. A build on OpenAI's API, using its chat component or your own code. Needs a developer and ongoing maintenance.

The rest of the numbers below mostly concern route 3, because that is where prices, limits and definitions differ most and where a wrong choice is most expensive.

Chatbot builders compared on the figures that set the bill

These are entry-tier list prices in USD from each vendor's own pricing page in October 2026. Prices, allowances and promotions move, so treat them as a snapshot and confirm on the live page.

Where two figures appear for one plan, the vendor's own page disagreed with itself or showed a billing-period discount; Wonderchat's page mentions a 17% discount for yearly payment, which probably explains its $32.50 against $39. Tidio's headline prices may likewise assume annual billing, since its page describes the annual option as "2 months free". Ask before you sign which price you will be charged.

Two other routes deserve a mention rather than a row. HubSpot's Customer Agent needs a Professional or Enterprise hub and, as of September 2026, uses 50 HubSpot credits (about $0.50) for each resolved conversation. Microsoft's Copilot Studio can publish agents to websites, with credit packs of 25,000 credits at $200 a month, but it suits businesses already built around Microsoft's admin tools rather than a first chatbot. Six alternatives to Chatbase and Botpress against Chatbase for a non-technical owner go deeper on the two names that come up most.

Turning 120 chats a month into each vendor's unit

Start from a concrete case: the website of an electrical contractor that gets about 120 chat conversations a month. Assume each has roughly five AI replies and that the owner expects the AI to settle about 60% of them without a person. Those are assumptions for the arithmetic, not benchmarks. Now convert the same traffic into each vendor's unit.

The same traffic lands anywhere from about $32 to about $150 a month depending on whose rules you read, a spread of nearly five times. Run the sum twice: once at today's volume and once at double. At 240 chats, Botpress passes 95% of its 250 conversations, the point at which its pricing page says a 100-conversation pack ($65) is added automatically, with no option to switch that off; Chatbase would need about 1,200 credits (above Hobby's 700), and CustomGPT.ai's 1,200 queries would exceed Standard's 1,000. Past an included limit, find out what the vendor does: bills extra, throttles the bot or switches it off. Tidio's page notes that its free allowance is one-time and that paid Lyro limits refresh 30 days after payment, which is a different rhythm from a calendar month.

Six questions that expose the real price before you sign

The comparison table gives you the headline. These questions, put to any vendor in writing, give you the rest. Keep the answers, because pricing pages change and a saved reply settles arguments later.

1. What exactly counts as one message, conversation, query or outcome? The same chat can be one unit with one vendor and six with another, and a "resolution" can mean a customer who simply went quiet.
2. What happens at the limit? Extra charges, throttling and switching off are three very different outcomes for a site that gets a busy week.
3. How often does the bot re-read my site, and can I trigger it by hand? A monthly re-read is no use if you changed your prices on the 3rd.
4. Can a visitor reach a person, and what do I receive when they ask? An email, a text, a ticket or nothing at all decides whether leads are rescued or lost.
5. Who owns the transcripts, how long are they kept and are they used for training? Get the retention period as a number of days, not a reassurance.
6. If I leave, can I export the knowledge base and the conversations, and is my data deleted? A vendor that cannot answer this plainly is one you may be stuck with.

If your site already runs on Shopify or Wix

Check the built-in route first, because it costs nothing extra and already knows your catalogue or pages.

• Shopify Inbox. The App Store listing shows it as free and describes an AI sales associate on your storefront that connects to your catalogue, inventory and policies, with tone and rules you control. You can run Inbox with or without the agent. The listing does not say how it handles a question it cannot answer or whether it escalates to a person. Shopify's help pages add that the agent needs the Basic plan or above with new customer accounts and can fall back on web search, so test it on your own returns and delivery questions before you leave it on.
• Wix Smart Chat. This is Wix's supported chat app, replacing Wix Chat (the older AI Site Chat can no longer be added to new sites). It answers from your site content and the training you provide, and you can switch to replying manually. Wix's help pages say it uses the AI credits included in your site plan and switches to offline mode when they run out, unless you change it to "Manual Chat 24/7" and answer yourself. Another Wix page promises "a free quota of AI conversations" to try it, without giving a number, so check what your own plan includes.

The trade-off is portability. A built-in assistant lives and dies with the platform, and you cannot take its training to a different site. If you expect to move platforms within two years, a standalone builder costs more now and saves a rebuild later.

The developer route and the parts of it that keep changing

OpenAI's own embeddable chat component is ChatKit. Its developer documentation describes a customisable chat embed: a developer adds a script to the page and your server creates a session through OpenAI's API for each visitor. Around it, things have moved. OpenAI is deprecating Agent Builder, the hosted workflow tool, and says it shuts down on 30 November 2026, while ChatKit itself remains available and new work is pointed at a custom server integration with your own agent code. The Assistants API, which some homemade website bots were built on, was sunset on 26 August 2026, with the Responses API named as the way forward for new work.

Token costs are small beside the build. OpenAI lists one of its small current models at $0.10 per million input tokens and $0.50 per million output tokens, and a mid-range flagship model at $2 and $10. Suppose one conversation sends about 20,000 input tokens (instructions, retrieved passages and history on every turn) and receives 1,500 tokens back. On the small model that is about $0.003 a conversation, or about $0.33 for 120 conversations a month. On the mid-range tier it is about $0.055, or $6.60 a month. The real costs are hosting, a developer's time and the maintenance that comes each time a product is retired, which is why I would send most small businesses to route 3 and keep route 5 for a team that already has a developer.

Moving a custom GPT's contents across before December

1. Copy the instructions out now, from the GPT's configuration page into a document, while the GPT still opens.
2. Collect the original knowledge files from your own folders. Do not rely on being able to pull them back out of the GPT.
3. Split public from internal. A website bot should know only what you would publish on a page. Strip staff-only discount rules, margin notes and supplier names. The same caution applies to a Gemini Gem, where anyone you share it with can read its instructions and uploaded files.
4. Rebuild the actions, since they do not transfer. A booking link or a CRM hand-off becomes the builder's own integration or a connector such as Zapier.
5. Rewrite the instructions for strangers. A staff assistant can be curt and assume context; a public one cannot.
6. Run the test questions below before the widget goes live, and again after any change.

The same discipline applies to everything else you feed the bot. Old PDFs with last year's prices, draft policies, internal procedures, supplier terms and anything containing customer details should stay out, because the bot cannot tell which version is current and will quote any of them. Two contradictory documents produce a confident answer that follows one of them at random. One tidy page per topic beats a folder of everything.

An instruction block to paste into whichever builder you pick

Every builder has a field for instructions, sometimes called the system prompt or persona. The wording below is a template for an electrical contractor; keep the structure and change the business details. For a longer version with test questions, see the AI chatbot prompt template for a small business.

You are the website assistant for [business name], an electrical contractor.
Say at the start of every chat that you are an AI assistant.
Answer only from the pages and documents in your knowledge. If the answer
is not there, say: "I'm not certain. The quickest route is to call [number]
or leave your details and [name] will reply by the next working day."
Never quote a price that is not in your knowledge. For quotes, explain that
a site visit is needed and collect: name, phone number, job address, a
one-line description and a photo if they have one.
If someone mentions burning smells, sparks or water near electrics, reply
only with [safety wording agreed by the owner] and our emergency number
[number].
Do not discuss other businesses or anything unrelated to our services.
If the visitor is upset or asks for a person, offer a call-back and stop.
Replies: plain English, the same spelling as our website, three sentences
at most unless asked for detail.

Three lines carry most of the weight. "Answer only from the pages" is what holds back invented answers. The fallback sentence gives the bot something safe to say instead of guessing. The red-flag line exists because a tool that is unsure on a fault report is a liability; the owner, not the AI, must decide that wording.

Ten test questions to run before the widget goes live

A realistic failure, with illustrative wording: a visitor asks, "How much to rewire a three-bed house?" and the bot answers with a confident price range your pages never mention. The cause is usually a missing page rather than a bad model: the bot had no pricing guidance, so it filled the gap. The fix is to publish a short page explaining how you quote (a site visit, what drives the price, how long a quote stays valid), re-sync, repeat the test and confirm the reply now says a visit is needed. The two replies, before and after (illustrative):

Before: "A full rewire of a three-bedroom house usually costs between $[low] and $[high] and takes about a week, depending on the property."

After: "Every rewire is priced after a site visit, because the age of the wiring, the number of circuits and access under the floors all change the cost. If you leave your name, phone number and address, [name] will call by the next working day to book a visit."

The first answer sounds helpful and commits you to figures nobody approved, which a visitor will screenshot and quote back. The second follows the quote-process page, collects the lead and hands it to a person, which is the bot's real job on a trades site.

The quieter failure is staleness. You update the contact page with new hours and the bot keeps quoting the old ones for weeks, because the plan re-reads your site monthly or only when you press the button. Test 10 catches it, and so does a monthly reminder to re-sync.

Which route for which business

Disclosure, data and a twenty-minute weekly review

Say at the start of every chat that it is an AI, which the instruction block above already does. If you have customers in the EU, the AI Act's transparency duties for chatbots have applied since 2 August 2026, so check your wording with an adviser; disclosure wording for a website chatbot has examples. Ask each vendor what happens to transcripts: how long they are kept, who can read them and whether they are used to improve the model. CustomGPT.ai's pricing page states "No training or sharing your data", and you should look for a comparable line on any builder you shortlist.

Then keep a routine. Once a week, spend twenty minutes on the transcripts the bot flagged as unanswered or handed to a person. For each one, either add the missing page, fix a wrong page or decide the question should always go to a human. Once a month, re-sync and rerun the ten tests. That routine is what separates a bot that earns its fee from one that quietly gives visitors wrong answers. If free plans are all you want to try first, what the free plans cap lists the ceilings before you commit.

Questions owners ask about putting AI on their site

Can I just link to my custom GPT from my website?

Only until it retires. A link opens ChatGPT in a new tab rather than a chat on your page, visitors leave your site to use it, and OpenAI has scheduled custom GPTs to stop running on 11 December 2026. A migrated copy does not keep the original's public sharing settings, so it will not carry the link forward.

Will a chatbot trained on my pages make things up?

It can. These tools search your content for relevant passages and write an answer from them, and when nothing relevant exists they may still produce something plausible. Instructions that say 'answer only from the knowledge provided', a published page for every common question and the ten test questions in this tutorial reduce the risk but never remove it.

Is my visitors' chat data used to train the AI?

It depends on the vendor, so read the data policy before you install anything. CustomGPT.ai's pricing page states 'No training or sharing your data'; check for the same promise, and for how long transcripts are kept, on whichever builder you pick. Tell visitors not to type sensitive details such as payment cards or health information into the chat.

How often does the bot re-read my website?

It depends on the plan. Wonderchat's pricing page lists manual recrawls on its free plan, monthly on Starter and Basic and weekly on Scale; CustomGPT.ai lists auto-sync from Premium. Whatever the schedule, trigger a re-sync by hand after you change prices, opening hours or policies, and put a monthly reminder in your calendar.

Can a website chatbot take bookings or payments?

Treat it as a front door, not a till. Most builders can hand a visitor to a booking link or a form, and some connect to calendars; Chatbase's pricing page, for example, lists Calendly, WordPress, Shopify and messaging integrations on every plan. Keep payments, refunds and quote approvals with a person or your normal systems, and test the hand-off as carefully as you test the answers.

Further reads

• How Much Does a Website AI Chatbot Cost, and Will It Pay Off? — What a website chatbot costs and when it pays for itself
• RAG vs Custom GPT vs Fine-Tuning: What Does Your Business Need? — How 'trained on your pages' really works, in plain English
• AI Chatbot for Plumbers: Answer Questions, Collect Photos, Refuse Jobs — A trades-business bot that answers, collects photos and hands over
• Best AI Chatbot for a Hotel Website: Score It on Real Guest Questions — Build a scorecard from past guest messages and test each hotel chatbot on it before paying, with accuracy and hand-off weighted highest.
• How to Use AI in Websites: Chat, Copy and Booking Costs for Local Firms — Chat, page copy and booking on a local firm's site: list prices, four sample monthly budgets, a chat fact sheet, copy checks and a four-week test.
• AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.

Sources: OpenAI help article on custom GPT retirement and migration, and OpenAI developer docs (ChatKit, Assistants API migration, API pricing); pricing pages for Chatbase, Botpress, Tidio, Wonderchat, CustomGPT.ai and Intercom; Shopify App Store listing for Inbox; Wix support articles on Smart Chat; Microsoft Learn on publishing Copilot Studio agents to a website (all checked October 2026).