Vibe Check – Light DOM vs. Shadow DOM: What designers need to know about accessibility
When designers think about accessibility, they often focus on color contrast, typography, and layouts. But there’s a deeper layer that impacts usability—how web components are structured under the hood. That’s where the Light DOM and Shadow DOM come in.
If content is hidden inside a Shadow DOM without proper accessibility considerations, it can become invisible to assistive technology, breaking the user experience. Let’s break down what designers need to know about these concepts and how to ensure accessibility stays intact.
A personal story – When a design looked accessible but wasn’t
I once worked on a project where we designed a sleek, modern modal window for an important user flow. It had proper contrast, intuitive labels, and clear call-to-action buttons. Everything seemed perfect—until we tested it with a screen reader.
Nothing was being announced. The focus didn’t shift to the modal, and users had no way to interact with it. After investigating, we found out the modal was built using a Shadow DOM, and key accessibility features weren’t exposed to assistive technology.
That’s when it became clear: a good design isn’t accessible if it’s trapped in a structure that hides it from assistive tech.
Elevate the vibe – Understanding the Light DOM and Shadow DOM
What is the Light DOM?
The Light DOM is the default structure of a webpage. Elements exist directly in the main document and follow standard styling and interaction rules. That means:
Screen readers can detect and announce content naturally.
Global styles (typography, buttons, links) apply without extra effort.
Keyboard focus moves predictably across elements.
What is the Shadow DOM?
The Shadow DOM is an isolated part of a webpage where developers can build self-contained web components. It’s great for keeping styles and scripts modular, but it also introduces accessibility risks:
Assistive technology may not see content inside a closed Shadow DOM.
Global styles won’t apply unless explicitly connected.
Keyboard navigation can break if focus management isn’t handled correctly.
Shadow DOM is useful for reusability, but if not designed with accessibility in mind, it can create serious barriers for users who rely on assistive technology.
Vibe up – How the Shadow DOM impacts accessibility
1) Screen readers may not detect hidden content
The problem:
If a component is placed inside a closed Shadow DOM, screen readers won’t be able to access it at all.
Even an open Shadow DOM requires proper ARIA attributes to expose content.
What designers need to do:
Work with developers to ensure critical content isn’t trapped inside a closed Shadow DOM.
Use labels, ARIA roles, and semantic HTML to connect visible elements with assistive technology.
2) Styles may not apply consistently
The problem:
The Shadow DOM prevents global CSS styles from affecting components inside it.
If designers expect certain typography or button styles to remain consistent, they might be overridden inside Shadow DOM components.
What designers need to do:
Communicate with developers about which styles should remain consistent across Light and Shadow DOM elements.
Ensure focus indicators and interactive states are designed inside the Shadow DOM.
3) Keyboard navigation can break
The problem:
Some Shadow DOM elements don’t automatically integrate with normal keyboard navigation.
If focus isn’t handled correctly, users may get "stuck" inside a component or be unable to interact with it at all.
What designers need to do:
Test all interactions using only a keyboard to ensure focus moves logically.
Ensure elements that require user input (forms, buttons) are reachable and operable via keyboard.
4) Interactive elements might not behave as expected
The problem:
Forms, buttons, and modal dialogs inside a Shadow DOM may not follow standard behavior unless explicitly connected to the main document.
Errors, validation messages, and feedback may not be announced to assistive technology.
What designers need to do:
Ensure interactive elements follow a logical flow and provide feedback that is detectable by screen readers.
Use ARIA live regions to announce changes dynamically.
Vibe boost – Designing with accessibility in mind for Shadow DOM
1) Ask if a component is using Shadow DOM
Not all designers are expected to know code, but asking developers whether Shadow DOM is in use can help guide design decisions.
2) Ensure visual affordances remain clear
If an element looks like a button, make sure it acts like one and is operable by keyboard and screen readers.
Use proper contrast and focus states to ensure accessibility remains intact.
3) Label everything clearly
Use explicit labels for buttons, inputs, and interactive elements to ensure they are recognized by assistive tech.
Example:
<custom-button aria-labelledby="save-btn"></custom-button>
<span id="save-btn">Save Changes</span>
4) Work with developers to test accessibility
Test with screen readers, keyboard navigation, and high contrast modes to ensure usability across different assistive tools.
If something doesn’t behave as expected, work together to find a solution.
Self-reflection – Evaluating your designs for Shadow DOM impact
Ask yourself:
Are my components and UI elements accessible to all users, regardless of how they interact with the page?
Is any critical content hidden inside a Shadow DOM without proper exposure to assistive tech?
Do all interactive elements have clear focus states and labels?
Have I tested my designs with keyboard and screen reader navigation?
If any of these raise concerns, it’s time to collaborate with your development team to ensure an inclusive experience.
Vibe in action – Making designs work with Shadow DOM accessibility
1) Apply what you’ve learned
Audit your designs for hidden content risks when Shadow DOM is in use.
Ensure that UI components maintain consistent styles and affordances.
2) Share the knowledge
Educate your design team about how Shadow DOM can impact accessibility.
Advocate for accessible design patterns that integrate well with web components.
3) Keep learning
Follow accessibility guidelines like WCAG and ARIA best practices.
Stay updated on how web components evolve in modern web development.
Test, iterate, and refine based on real-world feedback.
Vibing out
Designers play a critical role in ensuring web accessibility, even when working with complex technologies like Shadow DOM. While Shadow DOM is mostly a developer concern, its impact on accessibility affects the entire user experience.
By staying informed, collaborating with developers, and testing designs across different assistive technologies, designers can ensure that web components are both modern and inclusive.
Because when accessibility is considered at the design stage, everyone wins.
Support my work in accessibility
Creating accessible content takes time, care, and deep testing — and I love every minute of it. From writing blog posts to doing live audits and building checklists, everything I create is designed to make the digital world more inclusive.If something here helped you — whether it saved you time, taught you something new, or gave you insight into accessibility — consider supporting my work.
You can buy me a coffee to help keep this platform going strong:
Buy Me a Coffee
Every coffee goes toward:
- Creating new articles with accessibility tips, tools, and testing methods
- Covering hosting, software, and assistive tech costs
- Supporting free education for designers, developers, and testers
- Making a meaningful difference for people living with disabilities
Thanks for being part of this mission to build a more accessible web — one page at a time.