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WordPress

esc_attr( string $text ): string

Since
2.8.0
Source
wp-includes/formatting.php:4776

Escape a value for use inside an HTML attribute with esc_attr(), encoding quotes and angle brackets so dynamic data cannot break out of the attribute. In core since 2.8.0; the escaped string is passed through the attribute_escape filter before it is returned.

Escaping for HTML attributes.

Compatibility

WordPress
since 2.8.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$textstring

Return value

string
Escaped text.

Code examples

Every example is editable and runs in a real WordPress booted in your browser by WordPress Playground. Press Run, then edit the code: clicking away re-runs it. Nothing is sent anywhere until you do.

Build a form field with dynamic attribute values

Escape every dynamic value that ends up inside a quoted attribute, such as value, placeholder, or a class name pulled from settings.

$placeholder = get_option( 'myplugin_search_placeholder', 'Search products' );

printf(
	'<input type="search" name="s" placeholder="%s" value="%s" />',
	esc_attr( $placeholder ),
	esc_attr( get_search_query() )
);

esc_attr() only protects values inside quoted attributes; an unquoted attribute stays injectable no matter how you escape it. For href/src attributes use esc_url(), which also vets the protocol.

Performance profile

How much work a call to esc_attr() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Moderate

Reads stored settings via get_option(), cached per request but not free on a cold cache.

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
16

Executed per call on PHP 8.5. The body compiles to 16.

Plugin surface
1 hook

Third-party callbacks on 'attribute_escape' run inside this call, and their cost is not bounded by anything here.

Called by
50

50 places in core call this, so the cost is paid more often than your own code shows.

What it touches

  • hookthird-party callbacksapply_filters()called directly
  • optionoption read or writeget_option()one call below esc_attr()

Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost esc_attr() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always16wp_check_invalid_utf8(), _wp_specialchars(), apply_filters()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 16 instructions, 16 executed per call, 0 branches. The work does not change between versions.

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Hooks and filters fired · 1

One hook fires while esc_attr() runs, in this order:

  1. apply_filters( attribute_escape )filterline 4790 (+14 into the body)

    Filters a string cleaned and escaped for output in an HTML attribute.

Uses · 3

Used by · 50

Show all 50

Source code

View on Trac View on GitHub 

function esc_attr( $text ) {	$safe_text = wp_check_invalid_utf8( $text );	$safe_text = _wp_specialchars( $safe_text, ENT_QUOTES );	/**	 * Filters a string cleaned and escaped for output in an HTML attribute.	 *	 * Text passed to esc_attr() is stripped of invalid or special characters	 * before output.	 *	 * @since 2.0.6	 *	 * @param string $safe_text The text after it has been escaped.	 * @param string $text      The text prior to being escaped.	 */	return apply_filters( 'attribute_escape', $safe_text, $text );}

Changelog

Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data
Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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