<fieldset> Element

Technical Summary

Definition / Categories

fieldset is a form-associated element used to structure related controls; it is not itself a value-bearing control that represents every descendant's submission. Each descendant control keeps its own submission conditions.

Legend and content model

<fieldset>
  <legend>Contact method</legend>
  <label><input type="radio" name="contact" value="email"> Email</label>
  <label><input type="radio" name="contact" value="phone"> Phone</label>
</fieldset>

The HTML Standard permits an optional legend followed by flow content. The first legend element child supplies the group caption. Individual controls still need their own names, such as labels.

Form association

fieldset is a listed form-associated element. It may belong to an ancestor form, or its form owner may be set explicitly with the form attribute when the form is in the same document.

<form id="profile-form"></form>

<fieldset form="profile-form" name="contact-group">
  <legend>Contact method</legend>
  <input name="email" type="email">
</fieldset>

The name attribute is relevant when the fieldset is exposed through form.elements. It does not mean that the fieldset itself contributes a value to the entry list in the same way as its descendant controls.

Disabled propagation

<fieldset disabled>
  <legend>Not available yet</legend>
  <input name="enabled-by-fieldset">
</fieldset>

When a fieldset has the disabled attribute, descendant form controls are disabled except for controls that are descendants of the first legend element child. Nested fieldsets require the ancestor and first-legend exceptions to be considered together.

DOM Interface

HTMLFieldSetElement exposes APIs for inspecting the group's state, form owner, and collection of descendant form controls.

const group = document.querySelector('fieldset');

group.disabled;
group.form;
group.name;
group.elements;
group.willValidate;
group.validity;
group.checkValidity();
group.reportValidity();

Accessibility mapping

HTML-AAM maps fieldset through the group role mapping and associates its accessible name with the first rendered legend child. If the legend is hidden from the accessibility tree, it does not provide the accessible name for its parent fieldset.

A CSS border or a generic div cannot replace this structural relationship. Keep the group name in legend, and give each individual control its own accessible name.

Fact / Evidence

Normative claims and implementation observations are recorded separately, with their conditions and verification state.

Evidence

1. HTML Standard: The fieldset element — meaning, categories, content model, attributes, form owner, and DOM interface
2. HTML Standard: Enabling and disabling form controls — the disabled fieldset conditions
3. HTML Accessibility API Mappings: fieldset — group role and the legend-derived accessible name
4. Web Platform Tests: disabled element event propagation — test coverage that includes disabled fieldsets

Implementation Evidence

Browser behavior, WPT results, and accessibility observations are tracked separately from normative claims. Unrun items are not treated as reviewed.

Measured fixture / environment: The fixture contains a normal fieldset, a control inside the first legend, a control outside it, a disabled fieldset, a nested fieldset, and a fieldset using form and name inside or alongside <form id="evidence-form">. DOM and form APIs were measured in Chrome 152.0.0.0 (HeadlessChrome / Windows NT 10.0) on 2026-09-13.

Use the WPT repository for test mappings and HTML-AAM for the accessibility mapping baseline.

Coverage / Open Issues

• ReviewedMeaning, categories, content model, legend, disabled, form, and name at the specification level
• ReviewedPrimary HTMLFieldSetElement APIs and the HTML-AAM group / legend mapping
• OpenCross-browser comparisons for disabled propagation, nested fieldsets, and fieldset.elements
• OpenWPT execution, platform accessibility APIs, assistive-technology observations, compatibility, and historical changes

This is an initial coverage page. It does not claim complete verification of the fieldset specification, identical behavior across browsers, or identical announcements across assistive technologies.

Related surface

For a beginner-friendly introduction to grouping and legend, see the fieldset element page in Yugien. Form submission and form owners are covered by the form element; individual control association by the label element; and disabled control states by the input element.