AI chatbot for your website: build or buy, what it costs, and how it learns your content

You add an AI chatbot to your website by pasting a short script from a provider into your site, then giving the bot your own pages and documents to answer from. There are three routes: the AI add-on from a help desk vendor, a no-code chatbot builder, or a custom bot you build on a model API with your own documents.

Most small businesses have not done it yet. The US Census Bureau reported in May 2026 that between 17% and 20% of US businesses used AI from December 2025 to May 2026, and fewer than 20% of firms with four or fewer employees.

I set up an AI help desk for a fintech platform: I bought the agent instead of building one, and wrote the help centre it answers from. I’m chief product officer and forward deployed engineer at Instruxi, where the job is making AI work inside a client’s own systems. This note is for the owner choosing a chatbot for a website. If your real question is a support inbox, read AI customer service agent: what it can safely do instead.

How do you add an AI chatbot to your website?

Pick a route, then do the same four steps whichever you choose.

1. A help desk widget. A live chat vendor sells an AI agent as an add-on to its chat box and inbox. You get the widget, the inbox your team answers handovers in, and a bill per AI conversation.
2. A no-code builder. You upload files or point it at your website, it builds the bot, and you paste one script tag. You pay a monthly plan with a set number of message credits.
3. Custom, on a model API. A developer writes the chat, stores your documents in a database, and calls a model such as Claude through its API. You pay for hosting and the tokens you use, plus the build.

Then, on any route:

1. Collect the documents: your pages, price list, opening hours, payment rules, and what to do in an emergency.
2. Write the instructions: answer only from those documents, say which one it used, and hand over when nothing matches.
3. Test it with the questions customers really ask, including the awkward ones.
4. Paste the script into your site and read the first week of chats.

Try the three routes on a made-up London dental practice. Switch the route, take documents away, turn guessing on, and watch the answers, the sources, the handovers and the monthly bill.

How much does an AI chatbot for a website cost?

From about $45 a month to several hundred, depending on the route and how many people chat. US list prices, checked on each pricing page on 15 October 2026:

• Help desk widget, Tidio. The free plan includes 50 AI conversations with its Lyro agent, once. Lyro starts at $32.50 a month for 50 conversations paid yearly; billed monthly, the page lists $75 for 100, $210 for 300 and $700 for 1,000. The Starter plan for the inbox is $24.17 a month paid yearly. Any conversation with at least one AI reply counts, solved or not. The bigger help desks charge per resolution; I priced them in the customer service agent note.
• No-code builder, Chatbase. Hobby is $40 a month (or $32 paid yearly) for 700 message credits and 10 MB of training content. Standard is $150 a month (or $120 yearly) for 4,000 credits. Extra credits are $40 per 1,000, and removing its branding is $1,188 a year. Its FAQ says most models use 1 credit per reply and premium models 2 to 5.
• Custom, on a model API. Claude Haiku 5.5 costs $0.10 per million input tokens and $0.50 per million output tokens for prompts up to 100,000 tokens; Sonnet 5.5 is $2 and $10. Hosting on Vercel Pro is $20 a month, and a Supabase Pro database is from $25 a month.

A worked example: 300 chats a month, 3 replies each. The widget is $210 plus $24.17 for the inbox. The builder uses 900 credits: Hobby plus one top-up, $80. The custom bot sends about 3,000 tokens in and 250 out per reply: 2.7 million input tokens cost $0.27 and 225,000 output tokens $0.11 on Haiku 5.5, so $45.38 with hosting. On Sonnet 5.5 the tokens come to $7.65.

The custom route is cheapest to run and the only one with a build cost: a developer’s time, and someone to look after it. That trade is what decides most cases. For the cost of the website around it, see how much a small business website costs.

How does a chatbot learn your website’s content?

It does not memorise your site. Every time someone asks a question, it looks up the right passage and reads it. The technical name is retrieval.

1. Split. Your pages and files are cut into short passages: a paragraph of the price list, one row of opening hours.
2. Index. Each passage is stored so it can be found by meaning, as well as by its words. On a custom build that can be Postgres with pgvector.
3. Find. The customer’s question is matched against the index, and the closest three or four passages come back.
4. Answer. Those passages go to the model with your instructions, and it writes a reply from them and names the source.

If the right passage is missing, the model fills the gap with something that sounds right. That is why the documents come first. The instructions for the dental practice fit on one screen:

You are the website assistant for Larkspur Dental, Islington, London.
Answer ONLY from the passages below. Name the document you used.
If no passage answers the question, say so and offer to pass it to reception.
Say you are an AI if anyone asks, and at the start of every chat.
Never:
  - give medical advice, or suggest any medicine or dose
  - quote a price, time or policy that is not in a passage
  - ask for or accept card details
  - book, move or cancel an appointment; link to the booking page
If someone mentions swelling, bleeding, a knocked-out tooth or severe pain:
  tell them to call 020 7946 0321, NHS 111 out of hours,
  and 999 or A&E if swelling affects breathing or vision.

Passages:
{the 3 or 4 passages the search found}

The emergency line follows the NHS’s own advice on urgent dental care, which sends severe swelling that affects breathing or vision to 999 or A&E.

What should a website chatbot never do?

• Guess. In March 2024 The Markup found that New York City’s MyCity chatbot told business owners they could take a cut of their workers’ tips and go cashless, both against city law. Answer only from your documents, and hand over when nothing matches.
• Advise on health, money or law beyond what your documents say. Send people to a person or the right service.
• Promise what it cannot do: a price, a refund, a slot it has not checked.
• Take card details in chat. Send people to your payment page or reception.
• Pretend to be a person. The rules and the handover are in the customer service agent note.
• Go quiet. On a credit plan, a bot that runs out shows a message that it is unavailable. Set a top-up or an alert.

How do you know if the chatbot is working?

Read chats, not the dashboard. Every week:

1. Share answered with a source. Every unsourced answer is a possible wrong one.
2. Handovers, by reason. Each repeat reason is a missing page or a missing rule.
3. Wrong answers, from 20 chats read in full. The target is zero.
4. What chats led to: booking clicks, enquiries, calls.
5. Cost per useful chat: the monthly bill divided by chats that answered the question or started a booking.

A chatbot answers. An AI agent takes actions, which needs a different set of controls, covered in what agentic AI is.

Which route should you pick?

• Help desk widget if people already answer chats and you want one inbox for the bot and the team.
• No-code builder if you want it live this week, your documents are in good shape, and volume is modest.
• Custom if the bot needs to read your own systems, such as free appointment times, if volume is high, or if you want the data and the instructions in your own hands.

Questions people ask

Can I add ChatGPT to my website?

Not the ChatGPT app itself. The builders and the custom route use the same kind of model through an API, answering from your documents instead of the open web.

Is there a free AI chatbot for a website?

Tidio’s free plan includes 50 AI conversations, once. That is enough to test with your own questions before you pay.

Do I need a developer?

Not for a help desk widget or a builder: both give you a script to paste. You need one for the custom route, and for anything that reads your booking system or customer records.

How long does it take to set up?

The writing takes longest: the price list, hours and rules in plain words. With those ready, a widget or builder can be live the same day. A custom build takes days, with time to test it on real questions.

If you want an AI chatbot or help desk built and set up properly, write to me at m@tawfik.tv.