The <td> Element

Technical Summary

Definition / Content model

Basic definition of the td element

Item	Definition	Condition / scope
Meaning	A data cell in a table	th has the heading-cell meaning
Context	Child of a tr element	Participates in the table model as a cell
Content model	Flow content (general content such as text, paragraphs, and lists)	Each parent and child element has its own placement rules
Categories	Belongs to no specific content category	Its table-cell meaning is defined separately
End tag	May be omitted in text/html under conditions	When immediately followed by td or th, or when no content remains in the parent
DOM interface	HTMLTableCellElement	The th element uses the same interface

The standard permits omitting an end tag in some cases. In hand-written HTML, explicit tags make cell boundaries easier to follow. This is a choice for clarity; permitted omitted-tag markup is not automatically non-conforming.

Here, the table model means the rules HTML uses to place rows, columns, and cells and to detect overlap.

Span attributes and headers

Main attributes of td

Attribute	Specified meaning	IDL and boundary
colspan	Number of columns occupied by the cell	colSpan ranges from 1 to 1000; missing and invalid values default to 1
rowspan	Number of rows occupied by the cell	rowSpan ranges from 0 to 65534; 0 spans the remaining rows in the same row group
headers	IDs of related header cells	Unique, space-separated tokens; each token refers to a th in the same table

colspan is a positive integer up to 1000. rowspan is from 0 through 65534. The standard also sets how missing or invalid values work and what happens when JavaScript changes the DOM property. rowspan="0" does not mean zero rows: it spans the remaining rows in the same row group.

Spans change which positions a cell occupies in the table grid. A structure where cells overlap is a table model error. The fact that an HTML parser built a DOM does not by itself prove that the source markup conforms or that the table model is valid.

headers participates in specified table relationships; it is more than an arbitrary text attribute. Conforming markup points to th elements in the same table and does not make a cell refer to itself as a heading. Reading the attribute from the DOM alone does not establish how browser or platform accessibility APIs expose the relationship.

JavaScript DOM properties and cellIndex

HTMLTableCellElement is the interface JavaScript uses to work with a cell. It provides the colSpan, rowSpan, and headers properties. The shared interface also has scope and abbr, but those HTML attributes are conforming on th, not td.

cellIndex is the cell's position in its parent tr's cells list. When an earlier cell spans rows or columns, this number is not necessarily the cell's horizontal position in the table grid. It returns -1 when the element is not in a tr.

const cell = document.querySelector("td");
cell.cellIndex;  // Position in the parent tr's cell list
cell.colSpan;    // IDL value for colspan
cell.rowSpan;    // IDL value for rowspan

Facts / Evidence

Standard requirements, Accessibility mappings, and browser observations are recorded separately. Results from a selected fixture or WPT subset do not guarantee behavior across all implementations and table structures.

Evidence

1. HTML Standard: The td element — meaning, context, content model, end tag, and IDL interface
2. HTML Standard: Attributes common to td and th — colspan, rowspan, headers, and cellIndex
3. HTML Standard: Header and data cell semantics — explicit and automatic header assignment
4. HTML Standard: Forming a table — table grid, slots, and model errors
5. HTML Accessibility API Mappings: td — computed role by ancestor table role

Implementation Evidence

Specification claims are separate from observations in selected browsers, WPT tests, and Accessibility trees. The records below are limited to the measured environment, fixture, and tests.

WPT runs, browser Accessibility trees, platform accessibility APIs, and assistive-technology speech are separate evidence. No result is inferred for an unmeasured layer or combination.

Coverage / Open Issues

• ReviewedMeaning, context, content model, main attributes and IDL boundaries, and HTML-AAM role mapping
• OpenAll branches of header assignment, duplicate or missing IDs, and span boundaries / table model errors
• OpenWPT tests outside the selected subset, other browsers, and differing row-group or nested-table structures
• OpenPlatform accessibility APIs, speech and navigation with NVDA or other assistive technology, browser differences, and Expert-gap Review

This Topic is initial coverage. A specification mapping or result from one environment does not establish identical exposure or speech across browsers, operating systems, and assistive technologies.

Related surfaces

For a small beginner-friendly example, see How to Use the td Element. For heading meaning, scope, and headers, see the th Topic. For the table grid and parser recovery, see the table Topic; for its title, see the caption Topic.