wppaste
WordPress

site_url( string $path = '', string|null $scheme = null ): string

Since
3.0.0
Source
wp-includes/link-template.php:3505
Retrieves the URL for the current site where WordPress application files (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.

Description

Returns the 'site_url' option with the appropriate protocol, 'https' if is_ssl() and 'http' otherwise. If $scheme is 'http' or 'https', is_ssl() is overridden.

Compatibility

WordPress
since 3.0.0
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

$pathstringoptional
Path relative to the site URL. Default empty.Default: ''
$schemestring|nulloptional
Scheme to give the site URL context. See set_url_scheme().Default: null

Return value

string
Site URL link with optional path appended.

Performance profile

How much work a call to site_url() 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
8

Executed per call on PHP 8.5. The body compiles to 8.

Plugin surface
None

Nothing here hands control to plugin code.

Called by
30

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

What it touches

  • optionoption read or writeget_option()one call below site_url()
  • hookthird-party callbacksapply_filters()one call below site_url()

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 site_url() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
always8get_site_url()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 8 instructions, 8 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.

Uses · 1

  • get_site_url()Retrieves the URL for a given site where WordPress application files (e.g. wp-blog-header.php or the wp-admin/ folder) are accessible.

Used by · 30

Show all 30

Source code

function site_url( $path = '', $scheme = null ) {	return get_site_url( null, $path, $scheme );}

Changelog

Introduced in 3.0.0. 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 6.7.7 tag, from src/wp-includes/link-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
Corrections
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