Chatbot development pricing 2026: website, Zalo OA and Facebook
Messages arriving after hours are where revenue leaks most. Illustration generated with AI.
Ask three vendors to build the same chatbot and you can easily get three numbers that differ severalfold, with none of them explaining why. This article breaks a chatbot development quote into its parts, shows where the price shifts by channel, and lists the costs that always appear but rarely make the first page.
Chatbot development pricing in Vietnam in 2026 comes in three tiers: a scripted chatbot on an existing platform costs roughly 5 to 15 million VND to set up; a subscription AI chatbot has almost no upfront fee but runs a few hundred thousand to a few million VND a month; a custom-built AI agent starts from tens of millions of VND plus operating costs. The price shifts by channel because each platform has its own constraints: a website carries no platform fee, Zalo OA adds 1 to 6 million VND a year plus about 55 VND per message outside the 48-hour window, and a Facebook Page is bound by Meta's 24-hour window so the flow has to be redesigned. What drives the price is not the number of questions but data cleanliness, integration count, how much the bot may decide alone, and Vietnamese voice requirements.
What does a 2026 chatbot development quote actually cover?
A complete quote always has three blocks of money, not one number: a one-off setup fee to build the conversation flows and load your data, a monthly running fee covering the AI model plus hosting, and a platform fee if the bot lives on Zalo OA or a SaaS tool. The table below shows reference ranges as of August 2026 for small and mid-size businesses in Vietnam. The exact figure moves with the number of channels, the number of integrations, and how clean your existing data is.
| Level | What it does | Setup fee | Monthly running fee |
|---|---|---|---|
| Scripted chatbot on an existing platform | Button-driven flows: menu, price list, opening hours, repeat questions | 5 - 15 million VND | A few hundred thousand VND in platform fees |
| Subscription AI chatbot SaaS | Understands free-form questions, but hard to load deeply with your data and voice | Close to zero | A few hundred thousand to a few million VND |
| Custom-built AI agent | Knows your products, speaks your brand voice, connects CRM, orders and bookings | From tens of millions of VND | Model plus operations, scales with volume |
Why does the same bot cost differently on a website, Zalo OA and a Facebook Page?
The intelligence layer is the same, but each channel has its own technical constraints, so the workload differs. This is why a single quote lumping all three channels together is usually inaccurate.
- Website: no platform fee, but you have to handle anonymous visitors, keep context within a session, and fit the widget into an existing design. Usually the cheapest place to start.
- Zalo OA: add 1 - 6 million VND a year depending on plan, plus roughly 55 VND for every message sent outside the 48-hour window. In exchange, this is where Vietnamese customers actually message. Plan-by-plan detail is in our guide to Zalo OA chatbots for business.
- Facebook Page: the platform is free, but Meta only permits standard messages inside a 24-hour window from the customer's last message, and every new customer message reopens it. Outside that window you may only send a few approved message-tag types. The follow-up flow therefore has to be designed differently from Zalo, which is extra work rather than a copy-paste.
Each chat channel has its own constraints, so deployment cost differs. Illustration generated with AI.
What actually drives a chatbot quote up?
Not the number of questions the bot can answer, but four things people rarely ask about when requesting a quote. Understand these four and two quotes that differ threefold stop being a mystery.
- How clean your data is. If your price list lives across screenshots and old chat threads, someone has to normalize it first. This is usually the largest line item and the one most often left out of a quote.
- Number of integrations. A bot that only replies is cheap. A bot that checks stock, creates orders, books appointments or writes to your CRM adds a discrete block of work per connection, plus risk whenever the other system changes.
- How much the bot may decide on its own. Closing orders and applying discount codes requires a control layer, audit logs and clear handoff thresholds. A purely advisory bot needs none of that.
- Language and voice. Vietnamese shifts pronouns by context and is full of abbreviations and typos. Getting a bot to sound human requires dedicated training rather than defaults, as we cover in why Vietnamese AI agents need their own training.
Which costs sit outside the quote but still get paid?
The three items below rarely appear on the first page of a quote, yet they always surface within the first six months. Add all three before comparing two vendors.
- Your own team's time. Someone has to answer product questions, approve sample replies and correct what the bot gets wrong in month one. Usually a few dozen hours.
- Platform message fees. On Zalo that means messages outside the 48-hour window; on SMS or ZNS it is a per-template fee. This scales with customer volume, so it easily overshoots the estimate.
- Maintenance when data sources change. New prices, a new returns policy or a redesigned website all mean touching the bot. Ask explicitly whether this is billed monthly or per request.
Reading a quote: 5 items it must contain
A quote missing these will almost certainly grow past its final number. Take this list to the table before you sign.
- Conversation scope. How many topics the bot handles, who it hands off to beyond them, and how fast.
- Data sources and owner. Who normalizes the price list, policies and stock, and on what refresh cadence.
- A specific integration list. Name the actual systems, not a vague "CRM integration".
- Monthly running cost, itemized separately. AI model fees, platform message fees and hosting must be split out from setup.
- Handover and warranty. Who edits flows after launch, free for how long, and at what rate afterwards.
Read all five items carefully before signing. Illustration generated with AI.
Build it yourself or hire it out?
The answer depends on whether you have an operator, not on budget. If someone on your team knows the tooling and will own weekly bot edits, building on an existing platform is sensible and much cheaper. If nobody will take that job, a bot built once and abandoned will answer wrong and lose customers faster than having no bot at all. For teams without an operator, outsource the setup but keep the right to edit content, and insist on being handed the root accounts from day one. To size the revenue you are currently losing to slow replies before committing a budget, use the AI agent ROI calculator.
Frequently asked questions
What is the cheapest chatbot development quote?
The cheapest option is a scripted chatbot built on an existing platform, roughly 5 to 15 million VND as a one-off setup fee plus a few hundred thousand VND a month in platform fees. It handles menus, price lists and repeat questions through button-driven flows, but does not understand free-form questions.
Is a chatbot cheaper for a website or for Zalo OA?
A website is usually cheaper because there is no platform fee, only widget embedding and anonymous session handling. Zalo OA adds a plan fee of 1 to 6 million VND a year plus roughly 55 VND per message sent outside the 48-hour window, in exchange for reaching where Vietnamese customers actually message.
Why do two vendors quote tens of millions apart for the same brief?
Usually because the implied scope differs. The cheaper quote often omits data normalization work, the specific integration list and the monthly running cost, and all three still surface later. Compare quotes on the same five items: conversation scope, data sources, integration list, running cost and warranty terms.