HTML: The Living Standard

Where flow content is expected.

In this order: optionally a caption element, followed by zero or more colgroup elements, followed optionally by a thead element, followed optionally by a tfoot element, followed by either zero or more tbody elements or one or more tr elements, followed optionally by a tfoot element (but there can only be one tfoot element child in total).

interface HTMLTableElement : HTMLElement {
           attribute HTMLTableCaptionElement? caption;
  HTMLElement createCaption();
  void deleteCaption();
           attribute HTMLTableSectionElement? tHead;
  HTMLElement createTHead();
  void deleteTHead();
           attribute HTMLTableSectionElement? tFoot;
  HTMLElement createTFoot();
  void deleteTFoot();
  readonly attribute HTMLCollection tBodies;
  HTMLElement createTBody();
  readonly attribute HTMLCollection rows;
  HTMLElement insertRow(optional long index);
  void deleteRow(long index);
};

The table element represents data with more than one dimension, in the form of a table.

Tables have rows, columns, and cells given by their descendants. The rows and columns form a grid; a table's cells must completely cover that grid without overlap.

Authors are encouraged to provide information describing how to interpret complex tables. Guidance on how to provide such information is given below.

Tables must not be used as layout aids. Historically, some Web authors have misused tables in HTML as a way to control their page layout. This usage is non-conforming, because tools attempting to extract tabular data from such documents would obtain very confusing results. In particular, users of accessibility tools like screen readers are likely to find it very difficult to navigate pages with tables used for layout.

There are a variety of alternatives to using HTML tables for layout, primarily using CSS positioning and the CSS table model. [CSS]

Authors are encouraged to consider using some of the table design techniques described below to make tables easier to navigate for users.

table . caption [ = value ]

Returns the table's caption element.

Can be set, to replace the caption element. If the new value is not a caption element, throws a HierarchyRequestError exception.

caption = table . createCaption()

Ensures the table has a caption element, and returns it.

table . deleteCaption()

Ensures the table does not have a caption element.

table . tHead [ = value ]

Returns the table's thead element.

Can be set, to replace the thead element. If the new value is not a thead element, throws a HierarchyRequestError exception.

thead = table . createTHead()

Ensures the table has a thead element, and returns it.

table . deleteTHead()

Ensures the table does not have a thead element.

table . tFoot [ = value ]

Returns the table's tfoot element.

Can be set, to replace the tfoot element. If the new value is not a tfoot element, throws a HierarchyRequestError exception.

tfoot = table . createTFoot()

Ensures the table has a tfoot element, and returns it.

table . deleteTFoot()

Ensures the table does not have a tfoot element.

table . tBodies

Returns an HTMLCollection of the tbody elements of the table.

tbody = table . createTBody()

Creates a tbody element, inserts it into the table, and returns it.

table . rows

Returns an HTMLCollection of the tr elements of the table.

tr = table . insertRow(index)

Creates a tr element, along with a tbody if required, inserts them into the table at the position given by the argument, and returns the tr.

The position is relative to the rows in the table. The index −1 is equivalent to inserting at the end of the table.

If the given position is less than −1 or greater than the number of rows, throws an IndexSizeError exception.

table . deleteRow(index)

Removes the tr element with the given position in the table.

The position is relative to the rows in the table. The index −1 is equivalent to deleting the last row of the table.

If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an IndexSizeError exception.

Here is an example of a table being used to mark up a Sudoku puzzle. Observe the lack of headers, which are not necessary in such a table.

<section>
 <style scoped>
  table { border-collapse: collapse; border: solid thick; }
  colgroup, tbody { border: solid medium; }
  td { border: solid thin; height: 1.4em; width: 1.4em; text-align: center; padding: 0; }
 </style>
 <h1>Today's Sudoku</h1>
 <table>
  <colgroup><col><col><col>
  <colgroup><col><col><col>
  <colgroup><col><col><col>
  <tbody>
   <tr> <td> 1 <td>   <td> 3 <td> 6 <td>   <td> 4 <td> 7 <td>   <td> 9
   <tr> <td>   <td> 2 <td>   <td>   <td> 9 <td>   <td>   <td> 1 <td>
   <tr> <td> 7 <td>   <td>   <td>   <td>   <td>   <td>   <td>   <td> 6
  <tbody>
   <tr> <td> 2 <td>   <td> 4 <td>   <td> 3 <td>   <td> 9 <td>   <td> 8
   <tr> <td>   <td>   <td>   <td>   <td>   <td>   <td>   <td>   <td>
   <tr> <td> 5 <td>   <td>   <td> 9 <td>   <td> 7 <td>   <td>   <td> 1
  <tbody>
   <tr> <td> 6 <td>   <td>   <td>   <td> 5 <td>   <td>   <td>   <td> 2
   <tr> <td>   <td>   <td>   <td>   <td> 7 <td>   <td>   <td>   <td>
   <tr> <td> 9 <td>   <td>   <td> 8 <td>   <td> 2 <td>   <td>   <td> 5
 </table>
</section>

4.9.1.1 Techniques for describing tables

For tables that consist of more than just a grid of cells with headers in the first row and headers in the first column, and for any table in general where the reader might have difficulty understanding the content, authors should include explanatory information introducing the table. This information is useful for all users, but is especially useful for users who cannot see the table, e.g. users of screen readers.

Such explanatory information should introduce the purpose of the table, outline its basic cell structure, highlight any trends or patterns, and generally teach the user how to use the table.

For instance, the following table:

Characteristics with positive and negative sides
Negative	Characteristic	Positive
Sad	Mood	Happy
Failing	Grade	Passing

...might benefit from a description explaining the way the table is laid out, something like "Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column".

There are a variety of ways to include this information, such as:

In prose, surrounding the table

<p>In the following table, characteristics are given in the second
column, with the negative side in the left column and the positive
side in the right column.</p>
<table>
 <caption>Characteristics with positive and negative sides</caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

In the table's caption

<table>
 <caption>
  <strong>Characteristics with positive and negative sides.</strong>
  <p>Characteristics are given in the second column, with the
  negative side in the left column and the positive side in the right
  column.</p>
 </caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

In the table's caption, in a details element

<table>
 <caption>
  <strong>Characteristics with positive and negative sides.</strong>
  <details>
   <summary>Help</summary>
   <p>Characteristics are given in the second column, with the
   negative side in the left column and the positive side in the right
   column.</p>
  </details>
 </caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

Next to the table, in the same figure

<figure>
 <figcaption>Characteristics with positive and negative sides</figcaption>
 <p>Characteristics are given in the second column, with the
 negative side in the left column and the positive side in the right
 column.</p>
 <table>
  <thead>
   <tr>
    <th id="n"> Negative
    <th> Characteristic
    <th> Positive
  <tbody>
   <tr>
    <td headers="n r1"> Sad
    <th id="r1"> Mood
    <td> Happy
   <tr>
    <td headers="n r2"> Failing
    <th id="r2"> Grade
    <td> Passing
 </table>
</figure>

Next to the table, in a figure's figcaption

<figure>
 <figcaption>
  <strong>Characteristics with positive and negative sides</strong>
  <p>Characteristics are given in the second column, with the
  negative side in the left column and the positive side in the right
  column.</p>
 </figcaption>
 <table>
  <thead>
   <tr>
    <th id="n"> Negative
    <th> Characteristic
    <th> Positive
  <tbody>
   <tr>
    <td headers="n r1"> Sad
    <th id="r1"> Mood
    <td> Happy
   <tr>
    <td headers="n r2"> Failing
    <th id="r2"> Grade
    <td> Passing
 </table>
</figure>

Authors may also use other techniques, or combinations of the above techniques, as appropriate.

The best option, of course, rather than writing a description explaining the way the table is laid out, is to adjust the table such that no explanation is needed.

In the case of the table used in the examples above, a simple rearrangement of the table so that the headers are on the top and left sides removes the need for an explanation as well as removing the need for the use of headers attributes:

<table>
 <caption>Characteristics with positive and negative sides</caption>
 <thead>
  <tr>
   <th> Characteristic
   <th> Negative
   <th> Positive
 <tbody>
  <tr>
   <th> Mood
   <td> Sad
   <td> Happy
  <tr>
   <th> Grade
   <td> Failing
   <td> Passing
</table>

4.9.1.2 Techniques for table design

Good table design is key to making tables more readable and usable.

In visual media, providing column and row borders and alternating row backgrounds can be very effective to make complicated tables more readable.

For tables with large volumes of numeric content, using monospaced fonts can help users see patterns, especially in situations where a user agent does not render the borders. (Unfortunately, for historical reasons, not rendering borders on tables is a common default.)

In speech media, table cells can be distinguished by reporting the corresponding headers before reading the cell's contents, and by allowing users to navigate the table in a grid fashion, rather than serializing the entire contents of the table in source order.

Authors are encouraged to use CSS to achieve these effects.

4.9.2 The `caption` element

None.

As the first element child of a table element.

Flow content, but with no descendant table elements.

interface HTMLTableCaptionElement : HTMLElement {};

The caption element represents the title of the table that is its parent, if it has a parent and that is a table element.

When a table element is the only content in a figure element other than the figcaption, the caption element should be omitted in favor of the figcaption.

A caption can introduce context for a table, making it significantly easier to understand.

Consider, for instance, the following table:

	1	2	3	4	5	6
1	2	3	4	5	6	7
2	3	4	5	6	7	8
3	4	5	6	7	8	9
4	5	6	7	8	9	10
5	6	7	8	9	10	11
6	7	8	9	10	11	12

In the abstract, this table is not clear. However, with a caption giving the table's number (for reference in the main prose) and explaining its use, it makes more sense:

<caption>
<p>Table 1.
<p>This table shows the total score obtained from rolling two
six-sided dice. The first row represents the value of the first die,
the first column the value of the second die. The total is given in
the cell that corresponds to the values of the two dice.
</caption>

This provides the user with more context:

Table 1.

This table shows the total score obtained from rolling two six-sided dice. The first row represents the value of the first die, the first column the value of the second die. The total is given in the cell that corresponds to the values of the two dice.
	1	2	3	4	5	6
1	2	3	4	5	6	7
2	3	4	5	6	7	8
3	4	5	6	7	8	9
4	5	6	7	8	9	10
5	6	7	8	9	10	11
6	7	8	9	10	11	12

4.9.3 The `colgroup` element

None.

As a child of a table element, after any caption elements and before any thead, tbody, tfoot, and tr elements.

If the span attribute is present: Empty.

If the span attribute is absent: Zero or more col elements.

span

interface HTMLTableColElement : HTMLElement {
           attribute unsigned long span;
};

The colgroup element represents a group of one or more columns in the table that is its parent, if it has a parent and that is a table element.

If the colgroup element contains no col elements, then the element may have a span content attribute specified, whose value must be a valid non-negative integer greater than zero.

4.9.4 The `col` element

Categories:: None.
Contexts in which this element can be used:: As a child of a colgroup element that doesn't have a span attribute.
Content model:: Empty.
Content attributes:: Global attributes; span
DOM interface:: HTMLTableColElement, same as for colgroup elements. This interface defines one member, span.

If a col element has a parent and that is a colgroup element that itself has a parent that is a table element, then the col element represents one or more columns in the column group represented by that colgroup.

The element may have a span content attribute specified, whose value must be a valid non-negative integer greater than zero.

4.9.5 The `tbody` element

None.

As a child of a table element, after any caption, colgroup, and thead elements, but only if there are no tr elements that are children of the table element.

Zero or more tr elements

interface HTMLTableSectionElement : HTMLElement {
  readonly attribute HTMLCollection rows;
  HTMLElement insertRow(optional long index);
  void deleteRow(long index);
};

The HTMLTableSectionElement interface is also used for thead and tfoot elements.

The tbody element represents a block of rows that consist of a body of data for the parent table element, if the tbody element has a parent and it is a table.

tbody . rows

Returns an HTMLCollection of the tr elements of the table section.

tr = tbody . insertRow( [ index ] )

Creates a tr element, inserts it into the table section at the position given by the argument, and returns the tr.

The position is relative to the rows in the table section. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table section.

If the given position is less than −1 or greater than the number of rows, throws an IndexSizeError exception.

tbody . deleteRow(index)

Removes the tr element with the given position in the table section.

The position is relative to the rows in the table section. The index −1 is equivalent to deleting the last row of the table section.

If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an IndexSizeError exception.

4.9.6 The `thead` element

Categories:: None.
Contexts in which this element can be used:: As a child of a table element, after any caption, and colgroup elements and before any tbody, tfoot, and tr elements, but only if there are no other thead elements that are children of the table element.
Content model:: Zero or more tr elements
Content attributes:: Global attributes
DOM interface:: HTMLTableSectionElement, as defined for tbody elements.

The thead element represents the block of rows that consist of the column labels (headers) for the parent table element, if the thead element has a parent and it is a table.

This example shows a thead element being used. Notice the use of both th and td elements in the thead element: the first row is the headers, and the second row is an explanation of how to fill in the table.

<table>
 <caption> School auction sign-up sheet </caption>
 <thead>
  <tr>
   <th><label for=e1>Name</label>
   <th><label for=e2>Product</label>
   <th><label for=e3>Picture</label>
   <th><label for=e4>Price</label>
  <tr>
   <td>Your name here
   <td>What are you selling?
   <td>Link to a picture
   <td>Your reserve price
 <tbody>
  <tr>
   <td>Ms Danus
   <td>Doughnuts
   <td><img src="http://example.com/mydoughnuts.png" title="Doughnuts from Ms Danus">
   <td>$45
  <tr>
   <td><input id=e1 type=text name=who required form=f>
   <td><input id=e2 type=text name=what required form=f>
   <td><input id=e3 type=url name=pic form=f>
   <td><input id=e4 type=number step=0.01 min=0 value=0 required form=f>
</table>
<form id=f action="/auction.cgi">
 <input type=button name=add value="Submit">
</form>

4.9.7 The `tfoot` element

Categories:: None.
Contexts in which this element can be used:: As a child of a table element, after any caption, colgroup, and thead elements and before any tbody and tr elements, but only if there are no other tfoot elements that are children of the table element.; As a child of a table element, after any caption, colgroup, thead, tbody, and tr elements, but only if there are no other tfoot elements that are children of the table element.
Content model:: Zero or more tr elements
Content attributes:: Global attributes
DOM interface:: HTMLTableSectionElement, as defined for tbody elements.

The tfoot element represents the block of rows that consist of the column summaries (footers) for the parent table element, if the tfoot element has a parent and it is a table.

4.9.8 The `tr` element

None.

As a child of a thead element.

As a child of a tbody element.

As a child of a tfoot element.

As a child of a table element, after any caption, colgroup, and thead elements, but only if there are no tbody elements that are children of the table element.

Zero or more td or th elements

interface HTMLTableRowElement : HTMLElement {
  readonly attribute long rowIndex;
  readonly attribute long sectionRowIndex;
  readonly attribute HTMLCollection cells;
  HTMLElement insertCell(optional long index);
  void deleteCell(long index);
};

The tr element represents a row of cells in a table.

tr . rowIndex

Returns the position of the row in the table's rows list.

Returns −1 if the element isn't in a table.

tr . sectionRowIndex

Returns the position of the row in the table section's rows list.

Returns −1 if the element isn't in a table section.

tr . cells

Returns an HTMLCollection of the td and th elements of the row.

cell = tr . insertCell( [ index ] )

Creates a td element, inserts it into the table row at the position given by the argument, and returns the td.

The position is relative to the cells in the row. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the row.

If the given position is less than −1 or greater than the number of cells, throws an IndexSizeError exception.

tr . deleteCell(index)

Removes the td or th element with the given position in the row.

The position is relative to the cells in the row. The index −1 is equivalent to deleting the last cell of the row.

If the given position is less than −1 or greater than the index of the last cell, or if there are no cells, throws an IndexSizeError exception.

4.9.9 The `td` element

Sectioning root.

As a child of a tr element.

Flow content.

colspan

rowspan

headers

interface HTMLTableDataCellElement : HTMLTableCellElement {};

The td element represents a data cell in a table.

4.9.10 The `th` element

None.

As a child of a tr element.

Flow content, but with no header, footer, sectioning content, or heading content descendants.

colspan

rowspan

headers

scope

abbr