How Figma Built Accessibility Into a Canvas That Wasn't Designed for It

Figma published a detailed technical breakdown of how it engineered screen reader and keyboard support into its canvas-based editor — a genuinely hard problem, because the way Figma renders its canvas makes browser accessibility tools essentially blind to it. This isn't just an interesting engineering story. It's a direct lesson in a challenge you'll face the moment you start building your own app.

Why a Design Tool Had an Accessibility Blind Spot

Most web apps are built on HTML — buttons, paragraphs, images, all rendered by the browser. Browsers are good at this; they automatically generate what's called an accessibility tree, a behind-the-scenes structure that tells screen readers (software that reads the screen aloud for blind or low-vision users) what's on the page and how to navigate it.

Figma doesn't work that way. Like a video game engine, Figma takes over rendering entirely to power features like infinite zoom and real-time multiplayer. The payoff is a buttery-smooth canvas. The cost: the browser's accessibility tree was essentially empty. No matter how many layers existed in your file, the browser saw just one input field. Screen readers had nothing to grab onto.

This is the same trade-off many modern apps make when they reach for performance. It's worth understanding, because if you're vibe-coding your own product using a canvas, game-engine-style renderer, or heavily custom UI, you may inherit the same gap.

What Figma Actually Built

To fix this, Figma's team created a Mirror DOM — an invisible, parallel version of the design file written in standard HTML, kept in sync with the real canvas at all times. It mirrors the structure screen readers need without disrupting the visual experience for sighted users.

Four systems work together to make it run:

1. An internal accessibility tree — a cached summary of every layer in your file, with just the non-visual information a screen reader needs. It updates surgically as you edit, rather than rebuilding from scratch every time.
2. The Mirror DOM — a set of real HTML elements, generated from that internal tree and placed invisibly behind the canvas, that assistive technologies can actually read and navigate.
3. Bidirectional selection sync — when you click a layer on the canvas, the corresponding Mirror DOM element gets focus. When a screen reader user navigates to a Mirror DOM element, the canvas selection updates to match. The two sides stay in lockstep.
4. An announcement system — this alerts screen reader users to changes that a sighted person would notice visually: switching tools, nudging an object, toggling a panel.

One thoughtful detail: the Mirror DOM elements are actually laid out in space, not just hidden with a CSS trick. That's because spatial position carries meaning in a design file — screen magnifiers need to pan to the right place, and voice-control tools may display visual cues on screen. The position of every layer is calculated and passed through to the hidden HTML structure.

What This Means for You as a Builder

If you're a designer starting to ship your own app, Figma's behind-the-scenes work surfaces a few concrete things to keep in mind:

Accessibility doesn't come free with custom rendering. If you're using a low-code or AI-assisted tool that generates standard HTML and semantic elements — <button>, <nav>, <label> — you're in decent shape out of the box. But if your tool reaches for a canvas element or a fully custom renderer for performance or flexibility, ask explicitly: does this output accessible markup? Does it support keyboard navigation? Most vibe-coding tools today lean on frameworks that do generate real HTML, so this is less of a crisis than it sounds — but it's worth checking.

Prototypes and editor views need different accessibility logic. Figma's system is smart enough to strip editing-specific information (like autolayout frame wrappers) from the accessibility tree when serving a prototype to an end user. The end viewer just hears button labels and text content — not the internal structure of how the design is built. If you're shipping both an editor-style view and a consumer-facing view in your app, the same principle applies: what a user needs to hear is different from what a builder needs to see.

Keyboard navigation is table stakes, not a bonus. Figma specifically mentions keyboard accessibility as part of this work. Many users rely on keyboards exclusively — not just screen reader users, but power users and people with motor disabilities. If your app is fully mouse-dependent, you're locking people out. When you test your vibe-coded app, tab through it without touching the mouse. If you get stuck, your users will too.

The Honest Limits Here

Figma is describing work they've done on their tool — making Figma itself more accessible for designers who use assistive technology. It doesn't automatically make the designs produced in Figma more accessible. Getting the apps and websites you design in Figma to be accessible to end users is still a separate and ongoing challenge that happens in the handoff and build stages.

Still, this post is a rare, candid look at how hard accessibility can be when you're building something non-standard — and how much deliberate engineering it takes to get right. That's a useful gut-check for anyone building something new. Accessibility rarely happens by accident. But it doesn't have to be an afterthought either, as long as you ask the right questions early.