Evaluate JS

Evaluate JS

Type: page-evaluate  ·  Package: Browser v1.0.0  ·  Output: object

Executes JavaScript code within the context of the page and returns the result. It is an advanced activity: it gives you direct access to the DOM and the page’s APIs for cases that the other activities do not cover — reading a calculated value, manipulating a difficult element, or invoking a function on the page itself.

For users with JavaScript knowledge

Requires knowing JavaScript and understanding the page. For normal tasks (clicking, filling, reading text), use the specific activities — they are simpler and more robust. Fall back on Evaluate JS only when there is no other way.

How it works

Run the script on the page. It can be an expression (document.title) or a function that receives an argument ((arg) => arg.value * 2), in which case the value of the arg parameter is passed to it. Returns whatever the script returns.

Required parameters

Parameter	Editor	Description
script	multiline text	JavaScript expression or function body. Ex: document.title or (arg) => arg.value * 2.

Optional parameters

Parameter	Editor	Description
page	session	The page session. Omit it inside a body; outside, pass = page.
arg	expression	Argument passed to the script if the script is a function.

Output

Returns a object with the value returned by the script (text, number, list, etc.).

Example

Page Evaluate   script = "document.title"   → output: titulo

Page Evaluate
  script = "() => Array.from(document.querySelectorAll('.precio')).map(e => e.innerText)"
  → output: precios

Related activities

• Get Text / Get Attribute — simple and recommended options for reading data.
• Click — standard interaction without the need for JavaScript.