The <tbody> Element

Technical Summary

Definition, context, and content model

Basic definition of the tbody element

Item	Specification	Conditions and scope
Meaning	A row group for the table body	Groups body rows separately from heading and footer sections
Context	A child of table	Subject to the parent content model and ordering rules for caption, colgroup, thead, table body, and tfoot
Content model	Zero or more tr elements and script-supporting elements	An empty tbody is permitted by the content model
Start and end tags	May be omitted under specific HTML syntax conditions	The start tag can be omitted when the first content is a tr and it is not immediately preceded by a tbody, thead, or tfoot whose end tag was omitted. The end tag can be omitted before another tbody or a tfoot, or when the parent has no more content.
DOM interface	HTMLTableSectionElement	thead and tfoot use the same interface
Element-specific attributes	None	Global attributes are allowed

The table content model allows the body to be represented by zero or more tbody elements, or by one or more tr elements. When a tr token appears directly inside a table insertion mode, however, the HTML parser inserts a tbody in the DOM. Source conformance and the parser's DOM construction and recovery rules are separate.

Row groups and the table model

A row group is a unit of rows in the table grid. A cell cannot occupy slots in more than one row group. Therefore, rowspan="0" spans the remaining rows in the cell's own row group and does not continue into the next tbody.

Common row groups

Element	Typical purpose	Table-model category
thead	Contains the column-heading section	Row group
tbody	Contains the table's body rows	Row group; may occur more than once
tfoot	Contains footer rows such as totals	Row group

Do not infer a DOM row group from visual styling alone. Check the actual parent element and table model. The distinction also matters to the scope of th scope="rowgroup" and to the structure exposed to assistive technology.

DOM built by the parser

<table id="items">
  <tr><td>Apples</td></tr>
</table>

// DOM built by the HTML parser
table#items
└─ tbody  (inserted implicitly)
   └─ tr
      └─ td

When tr appears in the “in table” insertion mode, the parser inserts a tbody with no attributes and reprocesses the token. In the “in table body” insertion mode, a td or th appearing directly is a parse error; the parser inserts a tr with no attributes and reprocesses the cell token. These are parser-recovery behaviors, not authoring patterns to rely on.

HTMLTableSectionElement APIs

Common row APIs on tbody and table

Member	Return value or behavior	Range and boundary
tbody.rows	An HTMLCollection of the section's direct tr children	A live collection that reflects row insertion and removal
table.tBodies	An HTMLCollection of the table's child tbody elements	Does not include thead, tfoot, or tbody elements in a nested table
tbody.insertRow(index)	Creates a tr and inserts it into the section	-1 appends; an out-of-range index throws IndexSizeError
tbody.deleteRow(index)	Removes the selected tr from the section	-1 removes the last row; empty-section and index boundaries follow the method's index rules

const table = document.querySelector("table");
const body = table.tBodies[0];
body.rows.length;       // rows in this tbody
body.insertRow(-1);     // append a row to this tbody
body.deleteRow(-1);     // remove its last row

tbody.rows returns rows in that section. table.rows is a collection for the whole table. The names are similar, but their scopes differ.

Accessibility mapping

HTML-AAM maps native tbody to the WAI-ARIA rowgroup role. This exposes a structural grouping within a table; it is not a visible heading string. Record the browser, operating system, and table structure when observing the browser Accessibility tree or a platform API.

Facts and evidence

Specification claims and implementation measurements are recorded separately. A browser role query is not itself the normative HTML-AAM mapping or a platform Accessibility API measurement.

Evidence

1. HTML Standard: The tbody element — context, content model, tag omission, and section APIs
2. HTML Standard: Forming a table — row groups, cell slots, and row-span boundaries
3. HTML Standard: Table parsing modes — implied section and row insertion
4. HTML Accessibility API Mappings: tbody — rowgroup role and platform mappings
5. Web Platform Tests: the-tbody-element — section row collection and row methods
6. Web Platform Tests: rowspan-0.html — row-span behavior at a row-group boundary

Implementation Evidence

Specification requirements are recorded separately from browser observations, WPT runs, and Accessibility role queries. Each result applies only to its stated fixture, browser, and test selection.

A browser role/name query is not the same measurement as a platform Accessibility API or screen-reader speech. The tested layer and unmeasured scope are reported separately.

Coverage and open issues

• Specification checkedContent model, table ordering, row groups, table parser, HTMLTableSectionElement, and HTML-AAM mapping
• OpenImplementation evidence covers one selected fixture and browser environment; parser recovery branches and varied table structures remain untested
• OpenWPT evidence covers selected files. The exact upstream revision served by wpt.live and other browsers were not confirmed
• OpenPlatform Accessibility APIs, Windows UI Automation, assistive-technology speech, other operating systems, and Expert-gap Review

This Topic has initial coverage. Passing selected checks does not show that every HTML structure, browser, operating system, or assistive technology behaves the same way.

Related surfaces

For a beginner-friendly example, see How to Use the tbody Element in Yugien. The table Topic covers the table model; the header row group is covered in the thead Topic; summary row groups are covered in the tfoot Topic; tr covers rows and indexes; and th and td cover headers and data cells.