How to Use Inline SVG Icons in WordPress Without Extra Plugins.

SVG icons are lightweight, scalable, and easy to style with CSS. But by default, many WordPress themes and plugins load SVGs as <img> tags or background images — which limits styling and accessibility.

In this post, I'll show you how to render SVG icons with a custom function into your WordPress templates, allowing full control over their appearance and behavior.

✅ Why Inline SVG?

Rendering SVG as inline code gives you:

• Full CSS control (fill, stroke, hover effects)

• Better accessibility options

• No extra HTTP requests

• Animation capabilities

🧰 The Function: theme_get_svg()

Let’s walk through this function step by step so you understand how each part works.

function theme_get_svg($icon, $url = null, $args = [])
{
    $defaults = [
        "class" => "",
        "width" => "24",
        "height" => "24",
    ];

    $args = wp_parse_args($args, $defaults);

    // Determine the icon path
    if (!empty($url)) {
        // Fetch the SVG from an external URL (WordPress Media Library or external source)
        $response = wp_remote_get($url);

        if (
            is_wp_error($response) ||
            wp_remote_retrieve_response_code($response) !== 200
        ) {
            return "";
        }

        $svg = wp_remote_retrieve_body($response);
    } else {
        // Fetch the SVG from theme assets
        $icon_path =
            get_template_directory() . "/assets/icons/" . $icon . ".svg";

        if (!file_exists($icon_path)) {
            return "";
        }

        $svg = file_get_contents($icon_path);
    }

    $svg = preg_replace(
        "/<svg/",
        sprintf(
            '<svg class="%s" width="%s" height="%s"',
            esc_attr($args["class"]),
            esc_attr($args["width"]),
            esc_attr($args["height"])
        ),
        $svg,
        1
    );

    return $svg;
}

1. Default Arguments and Customization Options

$defaults = [
    "class" => "",
    "width" => "24",
    "height" => "24",
];

$args = wp_parse_args($args, $defaults);

We start by defining default attributes for the SVG — such as class, width, and height. The wp_parse_args() function merges the defaults with any custom attributes you pass when calling theme_get_svg().

👉 This makes the function flexible: you can override only what you need.

2. Load the SVG Content (From File or URL)

// Determine the icon path
    if (!empty($url)) {
        // Fetch the SVG from an external URL (WordPress Media Library or external source)
        $response = wp_remote_get($url);

        if (
            is_wp_error($response) ||
            wp_remote_retrieve_response_code($response) !== 200
        ) {
            return "";
        }

        $svg = wp_remote_retrieve_body($response);
    } else {
        // Fetch the SVG from theme assets
        $icon_path =
            get_template_directory() . "/assets/icons/" . $icon . ".svg";

        if (!file_exists($icon_path)) {
            return "";
        }

        $svg = file_get_contents($icon_path);
    }

This section determines where the SVG should come from:

• If you provide a $url, it fetches the SVG from a remote location (like WordPress Media Library).

• Otherwise, it looks for a local file in your theme’s /assets/icons/ folder.

Both approaches include error handling:

• For remote files, it checks for request errors or HTTP failures.

• For local files, it checks if the file exists.

3. Inject Attributes into the <svg> Tag

$svg = preg_replace(
    "/<svg/",
    sprintf(
        '<svg class="%s" width="%s" height="%s"',
        esc_attr($args["class"]),
        esc_attr($args["width"]),
        esc_attr($args["height"])
    ),
    $svg,
    1
);

This is where the magic happens. Instead of echoing a plain SVG, we inject our attributes into the first <svg> tag in the file, using preg_replace() with a limit of 1.

This gives us full control over:

• CSS styling (class)

• Size (width and height)

• Accessibility (aria-*, role, etc.)

Usage

You can now use it anywhere in your theme templates, just like this:

echo theme_get_svg(
	"iconname",
	null,
	array(
	    "class" => "custom-class",
	    "width" => "30",
	    "height" => "30"
    ),
);

Conclusion

Rendering SVG icons directly as inline code in WordPress gives you full control over styling, accessibility, and performance — without relying on external libraries or icon fonts.

With this function, you can streamline your workflow, improve page speed, and build a more maintainable front-end. Whether you're working on a custom theme or a client project, this approach keeps your codebase clean and flexible.

Feel free to tweak the function to suit your needs — and if you found this useful, consider sharing it with fellow developers!

Want to grab the full code? Check out the complete function on GitHub Gist:

👉 View theme_get_svg() on Gist