The <th> tag specifies a header cell in an HTML table. It must be used as a child element of <tr>, which in its turn is declared in the <table> tag. To define a standard data cell, the <td> tag is used.
The <th> tag can contain text, image, form, links or any other HTML element, that can be used in the body of the HTML document. The size of the table is automatically adjusted based on the size of its content.
In HTML tables, data is arranged vertically in columns. If you want to display the first row of the table as labels or headings, for the content in the table’s first row you must use <th> elements instead of <td> elements. By default, the content of the <th> tag is bold and centered. To change its look, you can use CSS styles. Table headings can also be easily styled independently from the rest of the table contents due to this element.
Note that all the rows in the table have an equal number of cells, which is equivalent to the number of cells in the longest row. If there are fewer cells in a row, then the browser will automatically fill the row, placing empty cells at the end of it.
If you need to emphasize that there is no data in other cells, then create cells without content where necessary.
The cells added by browser have no borders, and if they go after each other, they will be shown as one integrated cell.
Syntax
The <th> tag comes in pairs. The content is written between the opening (<th>) and closing (</th>) tags.
<table>
<tr>
<th>...</th>
</tr>
</table>Example of the HTML <th> tag:
<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
table {
width: 80%;
margin: 30px auto;
border-collapse: collapse;
}
tr:first-child {
background-color: #1c87c9;
color: #fff;
}
th,
td {
padding: 10px;
border: 1px solid #666;
}
</style>
</head>
<body>
<table>
<tr>
<th>Month</th>
<th>Date</th>
</tr>
<tr>
<td>June</td>
<td>18.07.2018</td>
</tr>
</table>
</body>
</html>Result
In this example, our headings are "Month" and "Date", that we define using <th> tags for each of them. Both tags we place in <tr>.
The colspan attribute is generally used with the <th> tag to let the content span over multiple columns. Let’s see this in action.
Example of the HTML <th> tag with the colspan attribute:
<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
table {
width: 80%;
margin: 30px auto;
border-collapse: collapse;
}
tr {
background-color: #1c87c9;
color: #ffffff;
}
th,
td {
padding: 10px;
border: 1px solid #666;
}
</style>
</head>
<body>
<table>
<tr>
<th colspan="2">Month and Date</th>
</tr>
<tr>
<td>Jun</td>
<td>18.07.2014</td>
</tr>
</table>
</body>
</html>In this example, the value of the colspan attribute is "2". It means that a header cell should span two columns.
Attributes
| Attribute | Value | Description |
|---|---|---|
| abbr | text |
Defines an abbreviated version of the content in a header cell, or an alternative text. Some user-agents, such as speech readers, may present this description before the content itself. Not supported in HTML 5. |
| align | left right center |
Aligns the content in a header cell.
Not supported in HTML 5. |
| axis | category_name | Categorizes cells having similar content.
Not supported in HTML 5. |
| background | background | Sets the background in a cell.
Not supported in HTML 5. |
| bgcolor |
rgb(x,x,x)
#xxxxxx colorname |
Defines the background color of a cell.
Not supported in HTML 5. |
| bordercolor | bordercolor | Sets the color of a border.
Not supported in HTML 5. |
| char | character |
Aligns the content in a header cell to a character. It is used only if the attribute is align="char".
Not supported in HTML 5. |
| charoff | number |
Sets the number of characters the content will be aligned from the character specified by the char attribute.
Is used only if attribute align="char".
Not supported in HTML 5. |
| colspan | number | Defines the number of columns a cell should span. The value of the attribute should be a positive integer. Default value is 1. |
| headers | header_id | Specifies a space-separated list of header cells which contains information about this cell. The value needs to correspond to the id of the header cell (set by using the id attribute). |
| height | % pixels |
Sets the height of a cell.
Not supported in HTML 5. |
| nowrap | nowrap | Specifies that the content inside a cell should not wrap.
Not supported in HTML 5. |
| rowspan | number | Specifies the number of rows a cell should span. The value of the attribute should be a positive integer. The default value is 1. It is not recommended to use values higher than 65534, as they will be clipped down to 65534. |
| scope | col colgroup row rowgroup auto |
Defines the cells that the header element (defined in <th>) relates to. Not supported in HTML 5. |
| sorted | reversed number reversed number number reversed |
Defines the sort direction of a column. Not supported in HTML 5. |
| valign |
top
middle bottom baseline |
Specifies vertical alignment of the content inside a cell.
Not supported in HTML 5. |
| width | % pixels |
Sets the width of a cell.
Not supported in HTML 5. |
The <th> tag also supports the Global Attributes and the Event Attributes.
How to style <th> tag?
Common properties to alter the visual weight/emphasis/size of text in <th> tag:
- CSS font-style property sets the style of the font. normal | italic | oblique | initial | inherit.
- CSS font-family property specifies a prioritized list of one or more font family names and/or generic family names for the selected element.
- CSS font-size property sets the size of the font.
- CSS font-weight property defines whether the font should be bold or thick.
- CSS text-transform property controls text case and capitalization.
- CSS text-decoration property specifies the decoration added to text, and is a shorthand property for text-decoration-line, text-decoration-color, text-decoration-style.
Coloring text in <th> tag:
- CSS color property describes the color of the text content and text decorations.
- CSS background-color property sets the background color of an element.
Text layout styles for <th> tag:
- CSS text-indent property specifies the indentation of the first line in a text block.
- CSS text-overflow property specifies how overflowed content that is not displayed should be signalled to the user.
- CSS white-space property specifies how white-space inside an element is handled.
- CSS word-break property specifies where the lines should be broken.
Other properties worth looking at for <th> tag:
- CSS text-shadow property adds shadow to text.
- CSS text-align-last property sets the alignment of the last line of the text.
- CSS line-height property specifies the height of a line.
- CSS letter-spacing property defines the spaces between letters/characters in a text.
- CSS word-spacing property sets the spacing between words.
Browser support
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