Most AI website builders work in one of three ways: they fill a prebuilt template with generated copy, they have a language model write the page's code directly, or they plan a design system first and compose sections on a visual canvas. All three can turn a description into a draft marketing page quickly. All three also hit the same walls: they can't supply your real photos or facts, and they don't build the software behind forms, stores or log-ins.
Knowing which kind you're using explains most of what you'll see: why some results look interchangeable, why others break on a phone, and why some let you change one heading without touching the rest.
The three kinds of AI website builder
1. Template fillers
The AI classifies your business, picks a template from a library, and writes headlines, paragraphs and button labels into its slots. Some also swap colors and fonts from a preset list.
- Good at: predictable, tested layouts. It's hard to get a broken page.
- Weak at: fit. The structure is the template's, not yours, so a page or section the template never planned can only be approximated. Sites built from the same library tend to look related.
2. Code generators
A language model writes HTML, CSS and often React from your prompt, and the tool renders what comes out. A chat assistant writing a page for you is this approach in its rawest form; what ChatGPT can and can't do for a website covers that route.
- Good at: flexibility. There's no template ceiling, and custom logic is possible.
- Weak at: seeing its own output. The model writes code as text, so overlaps, overflowing text on phones and spacing that drifts from page to page only show up once rendered. Fixing them means generating again or reading the code yourself.
3. Design-first canvas builders
The AI decides a design system first (palette, type scale, spacing, component styles), then builds pages section by section as design elements on a canvas you can see and edit. Code is generated from that design when you export.
- Good at: consistency, because every page draws from the same styles, plus visual editing and layouts planned for each screen width.
- Weak at: anything the canvas can't represent. It's more structured than raw code, which is the point, but also the limit.
FNJ's AI website builder belongs to this third group.
| Template filler | Code generator | Design-first canvas | |
|---|---|---|---|
| What the AI decides | Copy, sometimes colors | Everything, as code | Design system, structure, copy |
| Where structure comes from | The template | The model's output | A planned page list |
| How you edit | Swap content in slots | Re-prompt or edit code | Prompt, or click an element |
| Typical failure | Generic look, loose fit | Visual bugs, drift between pages | Limited to what the canvas supports |
What happens between your prompt and the page
Here's a design-first build step by step. The example is a specialty coffee roaster that sells beans wholesale to cafes and runs barista training.
- Reading the brief. The AI pulls out business type, audience, pages, tone and the main action. "Roaster selling wholesale to cafes" means the reader is a cafe owner, so the copy should talk about consistency and reliable supply, not tasting notes for home brewers.
- Reading the references. A reference turns taste into numbers. From a link, FNJ reads font families and type scale, colors by role (background, text, accent), corner radii, borders, shadows, navigation, heading and button styles, page structure and the social preview image. A screenshot carries the same signals visually; tall full-page screenshots are sliced so detail isn't lost. With several references, FNJ blends what they share and follows the first where they disagree.
- Planning the design system. Before any page exists, the builder settles pages, palette, typefaces and reusable styles. That's why the fifth page still matches the first.
- Structuring each page. Each page becomes a sequence of sections. The roaster's Wholesale page might get: hero, what partner cafes get (beans, equipment support, training), the roast schedule, how ordering works, and a call to action.
- Writing the copy. Copy is written for the business, not lifted from the reference. FNJ takes a reference's look and never its words, logos or images.
- Laying out each width. Real flex and grid containers reflow as the screen narrows; boxes pinned to fixed coordinates don't. FNJ designs every page at 1440, 810 and 390 pixels at once, each with its own type sizes and layout. Why screenshot-to-code breaks on phones explains the pinned-box problem.
- Generating code. At export the design becomes code. In FNJ that's a Next.js App Router project or static HTML, with no runtime script left behind.
Why a reference beats a description
"Minimal", "bold" and "premium" each describe thousands of possible designs. Given only adjectives, a model reaches for the most common interpretation, which is how so many AI-made sites end up with the same centered hero and three feature cards.
A reference pins down specifics: a large serif headline with tight line spacing, an off-white background, one rust-colored accent, square-cornered buttons. That's why FNJ won't start a new site without at least one reference, whether it's a screenshot, a link or your own project files. Designing from a website link covers what gets read from a URL.
Where AI website builders fall short
These limits apply to every kind, FNJ included.
They build presentation, not behavior
A marketing page is mostly layout and words. A booking system, a member area, a checkout or a searchable directory is software: it needs a server, stored data and security. FNJ builds marketing websites only, with no forms, store checkout, log-ins, databases or blog engine. The practical fix is a button that links to a dedicated tool: a hosted form, a scheduling link, a store.
They can't photograph your business
The AI doesn't know what your roastery looks like. Stock or generated images make a site feel like every other one in its category. FNJ has no stock library; it leaves styled photo spaces for your own uploads. Plan the photos early, because they're often the slowest part.
They don't know your facts
A language model writes the most plausible sentence, not the true one. Left to fill a gap, it produces confident specifics: years in business, customer counts, guarantees. Every figure needs checking against reality. Google's guidance on generative AI content makes the same point: fact-check what the AI wrote before you publish.
Brand nuance gets lost in words
"Our blue, but a little warmer than navy" rarely survives a prompt. Exact values do. FNJ reads a project ZIP or folder (design tokens, stylesheets, a Tailwind config, a brand guide, logo files), follows the brand exactly, and places your real logo when the project includes logo files.
Big re-generations undo good work
When a tool regenerates a whole page to change one heading, the parts you liked can change too. Look for precise editing. In FNJ you can select any element on the canvas and change its text, spacing, colors, layout or image, and each prompt can be undone from the chat while the editor is open.
Leaving can mean starting over
If a site can only run on the platform that built it, moving later means rebuilding. Ask what you actually get: a live site you rent, or source code you can host anywhere.
How to judge any AI website builder in one sitting
Run these tests on any builder before you commit to it:
- Build the same brief twice with two different references. Do the results look meaningfully different?
- Narrow the window to phone width. Does text reflow, or overlap and overflow?
- Ask for one small change. Does only that change?
- Search the copy for numbers and awards you never supplied.
- Check that each page has its own title and description.
- Export, if you can. Is it real source code, with no platform script required? Here's what FNJ's code export contains.
- Ask what happens to the site if you cancel.
Where FNJ fits
FNJ's builder is the design-first kind: references in, a design system planned, pages built at three widths on a canvas you can edit, and a Next.js or HTML project out that you host yourself. It's the wrong tool if you need an app, a store or member log-ins. If you want a marketing site you own, see how FNJ's AI website builder works.
Frequently asked questions
Do AI website builders use templates?
Some do, filling a prebuilt layout with generated copy. Others generate code directly, or plan a design system and compose sections on a canvas. Asking for a page or section the tool didn't suggest is a quick way to tell which kind you're using.
Why do so many AI-built websites look the same?
Because they're usually built from the same vague adjectives, and the AI falls back on the most common layout patterns. A specific reference, or your own brand files, gives the AI concrete type, color and spacing values to follow instead.
Can an AI website builder make a web app?
Marketing-site builders like FNJ don't build apps: no forms, log-ins, databases or checkout. An app needs real software behind it, which means a developer or a code-focused tool, plus hosting with a server and a database.
Is the code from an AI website builder any good?
It depends on how the builder works. Check for real flex or grid layouts rather than pinned boxes, a proper heading structure, a title and description per page, and no proprietary script the site needs in order to run.