prevent-element-src-loading

prevent-element-src-loading

Prevents targeted elements (script, img, iframe, link) from loading specific resources by intercepting src/href assignments and redirecting them to local mock data. Also neutralizes onerror handlers and error event listeners.

Parameters

Name	Description	Mandatory	Default
tagName	The type of HTML element to target. Accepted values: `script, img, iframe, link`.	Yes	n.a.
search	String or regex to match the URL in the `src`/`href`. Enclose in `/` for regex.	Yes	n.a.

Use cases

Neutralizing CV providers that use onerror attributes to detect blocked scripts/iframes.
Preventing tracking pixels or scripts while keeping the DOM structure intact.
Silently blocking resource loads that would otherwise trigger walls and errors.

Filter examples

Filter	Result
`prevent-element-src-loading 'script' /sdk/`	Replaces the `src` of any script containing "sdk" with an empty function.
`prevent-element-src-loading 'img' /banner_\d+/`	Replaces matching images with a transparent 1x1 GIF.
`prevent-element-src-loading 'iframe' 'message-alert'`	Prevents matching iframes from loading.

Debugging

#	Message	When	Meaning
1	`Wrapped setAttribute function`	After hooking setAttribute	setAttribute calls for this tag type are intercepted.
2	`Wrapped src/href property setter`	After hooking property	Direct assignments are intercepted.
3	`Wrapped onerror property setter`	During first call	onerror callbacks on matched elements are intercepted.
4	`Wrapped addEventListener`	During first call	error event listeners are intercepted.
5	`Replaced ... setter <<url>> → data:...`	When URL matches	The resource load was redirected to mock data.
6	`Replaced error event handler on [element] with () => {}`	When site adds error listener	The error listener was neutralized.