# How much does an AI chatbot cost? The four pricing shapes

> By Lawrence Dauchy, Founder, DFYe. Published 2026-08-17. 10 min read. Guides.
> Source: https://dfye.com/blog/how-much-ai-chatbot-cost/
> Language: en

Per message, per seat, per resolution, or a flat licence with your own key. Which one you pick decides what a good week does to your bill.

**TL;DR.** An AI chatbot costs between nothing and several hundred a month, and the range is not about quality. Four pricing shapes exist and each fails differently: per message scales with your traffic rather than your revenue, per seat charges for humans you may not want, per resolution lets the vendor define resolved, and a flat licence with your own key moves the variable cost onto the model provider's published per-token price. The model itself is usually the smallest line.

An AI chatbot costs anywhere from nothing to several hundred a month, and the four
pricing shapes behind that range matter far more than the number. Per message, per
seat, per resolution, or a flat licence where you bring your own model key. The model
calls themselves are usually the smallest line: a single answered question is roughly
**1,500 tokens in and a few hundred out** once you are pasting retrieved passages into
every request, which for a few thousand conversations a month lands in tens of euros
rather than hundreds.

So the useful question is not what it costs. It is what a bad month costs, and only
one of the four shapes gives you a comfortable answer.

## What are you actually paying for?

Four things, bundled differently by each vendor. Reading which of the four is doing the
work in a given price is most of the comparison.

| Pricing shape | What you pay for | What makes the bill move |
|---|---|---|
| Per message | Each exchange with a visitor | Your traffic, including traffic you did not want |
| Per seat | Human agents with logins | Team size, including the person who logged in once |
| Per resolution | Conversations the bot closed | The vendor's definition of resolved |
| Flat licence, your own key | The software, once or yearly | Nothing. The model bill is separate and public |

The bottom row is the only one where the software price and the usage price are
separated, and separating them is what makes both of them checkable. You pay the
vendor for software and the model provider for tokens, at a rate published on a page
you can read without a sales call.

The per-resolution row deserves a specific warning. Resolved is not a fact, it is a
definition, and the party defining it is the party billing you. Ask exactly what
counts: a visitor who closed the window, a conversation with no follow-up within an
hour, a thumbs up. Each of those produces a different invoice from identical
behaviour.

## What does the model itself cost to run?

Less than almost everybody assumes, and it is worth doing the arithmetic once so the
number stops being scary.

A retrieval answer is two calls. One small
[embedding](https://platform.openai.com/docs/guides/embeddings) request to turn the
question into numbers, which is priced in fractions of a cent, and one completion
request carrying the question plus the passages you retrieved. That completion is the
expensive half, and retrieval is what makes it expensive: you are sending four
passages of your own content with every single question.

Assume 1,500 tokens in and 300 out per answered question, which is a normal shape for
a retrieval bot. A thousand conversations a month is then well inside the tens of
euros at published rates. Two thousand is still tens of euros. The number only becomes
interesting at volumes where you would also be hiring.

Two things move it more than the model choice does. Caching identical questions, since
the same four questions arrive constantly and a cached answer costs nothing. And how
many passages you paste in: four short ones answer as well as eight long ones and cost
half as much.

## How do you estimate your own volume?

By counting what you already get, then expecting more, which is the part that catches
people out.

Start with the month you have. Count the support emails, the contact form submissions
and, if you run live chat, the conversations. That is your current demand and it takes
twenty minutes to pull.

Then adjust upward rather than down. A chat widget does not simply move existing
questions to a new channel; it lowers the cost of asking, so people ask things they
would never have written an email about. Sizing, compatibility, whether something is
in stock in a colour. Those questions were always there and were being answered by a
visitor guessing or leaving. Your first month with a widget will usually carry more
total contacts than your last month without one, and that is the product working
rather than failing.

Which is exactly why the shape matters. On a flat licence that increase is free. On
per-message pricing you have just made your own bill go up by succeeding.

Two caps are worth setting on day one, before any of this is theoretical. Set a hard
spend limit in your model provider's dashboard, so a runaway loop or a scraper cannot
spend a quarter's budget overnight. And put a rate limit on your own endpoint, per
session and per address, which you can only do if requests pass through a server you
control rather than going from the browser to the model.

Neither takes long and both are the kind of thing nobody does until the first
surprising invoice.

## What happens on a bad month?

The shapes separate, which is the entire argument for caring about them.

| Scenario | Per message | Flat licence with your own key |
|---|---|---|
| A quiet month | Cheap, and you notice you are paying for little | Same fixed fee, plus almost no tokens |
| A launch week | Bill rises with attention, not with orders | Same fixed fee, plus a small token bump |
| A scraper finds your widget | Bill rises for traffic that will never buy | Same fixed fee, plus tokens you can rate-limit |

Row three is not hypothetical. A chat endpoint is an open invitation to anything
automated, and the defence is a rate limit on your own server, which you only have if
the requests pass through a server you control.

The pattern across all three rows is the same. Per message ties your cost to
attention, and attention is not revenue. A delivery delay that makes three hundred
customers ask the same question is your most expensive day under that model and your
least profitable one, at the same time.

None of which makes per-message pricing dishonest. It makes it a risk to accept
deliberately, with a cap configured, rather than by default.

## What costs are not on the pricing page?

Three, and the third is the one people discover late.

**Overage rates.** A bundle of messages has a price per message inside it and a
different price above it, and the second number is often several times the first. It
is usually in the terms rather than on the pricing page. Ask for it.

**Seats you forgot.** Per-seat pricing accumulates quietly: somebody is added for a
busy fortnight and is still billed a year later. This is a calendar reminder rather
than a technical problem, but it is real money and nobody owns it.

**The cost of leaving.** Not a fee. The question is whether you can export your
transcripts and your knowledge base in a format usable somewhere else. If you cannot,
the true price of the product includes never being able to change your mind, and that
is worth more than any monthly difference. Test it with one support email before you
commit, not on the day you want to move.

Our own position on all of this is on [pricing](/pricing/), and what you are permitted
to do with the software is in [the licence](/eula/).

## When is the free option the right answer?

More often than the paid pages suggest, and specifically when you want the decisions.

[AI Engine](https://wordpress.org/plugins/ai-engine/) is free, mature and sits at
100,000 installs against the
[plugin API](https://api.wordpress.org/plugins/info/1.2/). You bring your own key,
which means the per-token cost reaches you unmarked up, and you choose the model,
build the knowledge base and style the widget. If those are choices you want to make,
this is the best value in the category and nothing paid will beat it on price.

What free costs you is attention, and that is a genuine cost rather than a rhetorical
one. The setup is a day or two. The tuning is ongoing. The checking, which is the part
that decides whether any of this was worth doing, is yours forever. People who enjoy
that get an excellent deal. People who wanted it answering by Friday have bought a
project.

Paid products are selling that gap and some of them are worth it. The honest way to
judge one is to ask what it does that you would otherwise have to build, and to notice
when the answer is mostly hosting.

## When should you not be paying for this?

Three situations, and the first is the most common by a distance.

If you get fewer than roughly ten questions a week, every option here costs more in
attention than it saves in answering. An email address and a good FAQ page is correct
and stays correct longer than most people expect.

If your site does not contain the answers, you are paying to index nothing. Writing
the three pages that cover most questions, delivery, returns and sizing, is an
afternoon and it improves the site for every visitor who never opens a chat window.
Pay for software after that, not before.

And if the cost you are trying to remove is a person, look closely at what that person
actually does. Automating the repeated questions is real savings; automating judgement
is not, and a product priced on resolutions has an incentive to describe the second as
the first.

For the shortlist itself, the market and the review data are in
[826,000 WordPress sites and almost no AI](/blog/wordpress-chat-plugin-market-2026/),
and what this category actually contains is in
[what an AI chatbot for a website actually is](/blog/ai-chatbot-website/).

## Quick answers

### How much does an AI chatbot cost?

Anywhere from nothing to several hundred a month, and the spread is about pricing shape
rather than quality. The free route is a plugin where you bring your own model key and
pay the provider directly for tokens, which for a small site is usually tens of euros a
month at most. The paid route is a product that adds the software, the hosting and the
support on top, priced per message, per seat or per resolution.

### What is the cheapest way to run a chatbot on my website?

A free plugin plus your own model key. You pay the model provider directly at their
published per-token rate with nothing marked up, and the software costs nothing. What
it costs instead is your attention: you build the knowledge base, write the prompt,
style the widget and decide the refusal behaviour. That is a day or two of work, which
is cheap if you enjoy it and expensive if you do not.

### Why is per-message pricing risky?

Because your support load does not scale with your revenue. A product that briefly goes
viral, a delivery delay that makes three hundred people ask the same question, or a
scraper hitting your widget all raise the message count without raising your income.
Per message means your worst month and your best month can be the same bill, arriving
for opposite reasons.

### How much do the AI model calls actually cost?

Usually the smallest line on the invoice, and smaller than people expect. A single
answered question is roughly 1,500 tokens going in once you are pasting retrieved
passages into the request, and a few hundred coming back. At published rates that puts
a few thousand conversations a month in the tens of euros, not the hundreds. The
software and the support around it cost more than the model.

### Are there hidden costs in chatbot pricing?

Three that appear regularly. Overage rates above your message bundle, which are often
several times the in-bundle rate. Per-seat charges for team members you added for one
week. And the cost of leaving, which is not money: if you cannot export your
transcripts and knowledge base in a usable format, the real price of the product is
that you now cannot change your mind.

### Is a free AI chatbot actually free?

The software is. The tokens are not, and neither is your time. Free plugins hand you
the model key decision, which is genuinely better for cost control because nothing is
marked up, but the setup, the tuning and the ongoing checking are yours. Free means you
pay in attention instead of money, and that is a real trade rather than a trick.

## Sources

- [OpenAI: embeddings](https://platform.openai.com/docs/guides/embeddings)
- [OpenAI: function calling](https://platform.openai.com/docs/guides/function-calling)
- [AI Engine on the WordPress.org plugin directory](https://wordpress.org/plugins/ai-engine/)
- [Tidio on the WordPress.org plugin directory](https://wordpress.org/plugins/tidio-live-chat/)
- [WordPress.org plugin API, the install figures](https://api.wordpress.org/plugins/info/1.2/)

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