Reading the Accessibility Tree to Debug ARIA
Verify roles and states in the browser inspector.
Reading the Accessibility Tree to Debug ARIA is a free Web Accessibility Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Web Accessibility Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
What the Accessibility Tree Is
The browser builds an accessibility tree from your DOM. It is the stripped-down version that screen readers actually read.
Why Debug It Directly
Looking at the tree shows the truth: the real name, role, and state of an element, not what you hoped your markup produced.
Open Chrome DevTools
In Chrome, open DevTools and pick the Accessibility pane in the Elements panel. Select any node to inspect its computed a11y data.
Read the Computed Properties
The pane shows the element's computed role and name plus its states. This is exactly what assistive tech will announce.
Firefox Has One Too
Firefox ships an Accessibility inspector as its own DevTools tab, with a handy check for common contrast and naming issues.
Catch the Missing Name
The most common bug the tree reveals is a control with an empty name. An icon button shows no name, so users hear only button.
<button><svg>...</svg></button>
<!-- name in the tree: empty -->Spot the Wrong Role
If you expected a button but the tree says generic, your role never applied. Fix the markup before adding more ARIA on top.
Verify State Updates Live
Toggle your widget and watch the tree. If aria-expanded does not flip in the pane, your JavaScript is not syncing the state.
Find Hidden Subtrees
An element set to aria-hidden drops out of the tree entirely. Use this to confirm decorative content is correctly skipped.
Tree, Then Real Screen Reader
The tree shows intent, but a real screen reader shows experience. Use the tree to debug, then confirm with NVDA or VoiceOver.
A Quick Debug Loop
Build the habit: change markup, reselect the node, read its name, role, and state. Tight loops catch ARIA mistakes fast.
Quick Check
Your custom button reads as just button with no label. Where do you confirm the missing name?
Recap: Inspect the Truth
You learned the accessibility tree is what AT really reads. Inspect it in DevTools to verify names, roles, and states, then confirm with a real screen reader. 🔍
Frequently asked questions
Is the “Reading the Accessibility Tree to Debug ARIA” lesson free?
Yes — the full text of “Reading the Accessibility Tree to Debug ARIA” is free to read here on the web, and the Web Accessibility Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Web Accessibility Academy course, upgrade to CoddyKit PRO.
What will I learn in “Reading the Accessibility Tree to Debug ARIA”?
Verify roles and states in the browser inspector. You practise Web Accessibility Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Web Accessibility Academy?
No prior experience is required. Web Accessibility Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Reading the Accessibility Tree to Debug ARIA” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Web Accessibility Academy lesson?
Yes. Every Web Accessibility Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- The First Rule: No ARIA Beats Bad ARIA
- Roles Define What a Thing Is
- States and Properties: expanded, checked, disabled
- Reading the Accessibility Tree to Debug ARIA