We have all been in that design review. The prototype looks perfect. Stakeholders approve it. The engineer starts building. Three sprints later, QA flags that the disabled state is wrong, the focus ring is invisible, and the loading state never received a spec. Everyone blames everyone else, but the root cause is the same: the prototype never showed those states in the first place.
Click-through tools are useful for a lot of things. Component testing is not one of them.
What a Click-Through Prototype Actually Shows You
When you build a prototype in a click-through tool, what you are really building is a slideshow. Each screen is a static image. A click on a hotspot advances to the next image. The experience feels like an app, but the fidelity is closer to a storyboard than a component.
What this means in practice: the prototype only shows the states you explicitly drew. If you drew the button in its default state and its hover state, those are the only states that exist in the prototype. The disabled state, the focus state, the loading state, the error state: those either got a separate artboard (which someone has to remember to link) or they got skipped entirely.
This is fine for concept validation at the start of a project. It is a problem when you use it as the source of truth for what a component should do.
The States That Only Appear in HTML
Consider what browsers do that design tools cannot simulate:
Focus behavior. Every interactive element in a browser gets a focus state when keyboard users tab to it. That focus state uses a ring or outline, and it needs to be visible. A Figma component might include a focus variant, but the prototype does not apply it automatically when you tab through. An HTML prototype does, because it is a real browser rendering real elements.
Disabled state behavior. A disabled button in a design tool is just a button with reduced opacity. In HTML, a disabled button has no pointer events, a different cursor, and an aria-disabled attribute that changes how screen readers announce it. That set of behaviors cannot be approximated in a click-through prototype.
Responsive layout shifts. A design file has a fixed artboard width. The component you draw at 1280px width might wrap, overflow, or collapse at 768px. A click-through prototype only shows the width you drew. An HTML prototype running in a browser can be resized, and you see the real behavior of the component at every breakpoint.
Text overflow. Designers use real copy in prototypes, which means the prototype never encounters the three-word label that breaks the card layout or the product name that does not fit in the badge. HTML prototypes with dynamic content expose these edge cases immediately.
A Concrete Case: Button with Six States
We worked with one of our early-access teams on a button component that had six states: default, hover, focus, active, disabled, and loading. Their Figma prototype covered two of them, default and hover, linked via an interaction. The other four states existed as artboards in the Figma file but were not connected to the prototype flow.
The engineer built the component from the spec annotations, correctly handling all six states. The QA review caught three discrepancies: the focus ring color did not match the token value, the loading state lacked the accessible text swap that screen readers need, and the disabled state still fired click events in some edge cases.
None of these problems were visible in the prototype. All three would have been caught immediately if the design review had used an HTML prototype built from the actual token file.
Token Fidelity Is Fidelity
Here is what changes when you prototype in HTML with real design tokens. The button in the prototype uses --color-primary and --radius-md from the same token file your production components will use. If the token value is wrong, you see the wrong color in the prototype, not just in production. If the spacing token creates a layout problem, you see it at prototype stage.
This is the insight behind the prototype builder in DesignVerse. When you generate a prototype from your design system, it is not a screenshot of your components. It is your components, rendered by a browser, using the same token values. The prototype is not adjacent to the implementation. It is part of the same pipeline.
That matters for design reviews. When a stakeholder approves the prototype, they are approving something that directly represents the production artifact. There is no translation layer between what they saw and what gets shipped.
Click-Through Tools Are Still Useful (Boundary Statement)
This is worth being precise about. We are not saying click-through tools are bad or that you should stop using them. They are good at specific things: sharing a flow with stakeholders who cannot open a browser, validating information architecture early in a project, mapping out multi-screen navigation before any components exist.
The problem is using them for component testing, which is a different job. Concept validation needs speed and shareability. Component testing needs behavioral fidelity. Using a tool built for the first job to do the second job is where the state-coverage gaps come from.
The appropriate moment to move from click-through to HTML prototyping is when the design has stabilized enough that you are reviewing component behavior rather than user flow logic. At that point, the click-through prototype has done its job and a higher-fidelity format takes over.
Starting Without Rebuilding Everything
You do not need to replace every click-through prototype in your project history. The highest-value candidates for HTML prototypes are the components with the most interactive states: forms, buttons, navigation, data tables, and any component where error and loading states carry significant UX weight.
Start by generating HTML prototypes for your core input components. Wire them together into the two or three flows that are most likely to expose state-handling bugs. Run keyboard navigation through those flows and see what you find.
In our experience, most teams catch three to five component issues in their first HTML prototype walkthrough that had been invisible in click-through tool reviews for months. Not because the designers missed them, but because the tool they were using was structurally incapable of showing them.
The prototype format is a design decision. Choosing a format that matches the fidelity requirements of your review is part of the craft.