HTML beforeprint DOM Event: Reference and Examples

When someone interacts with a webpage, the browser sends events to the relevant JavaScript code. The beforeprint event happens when the browser is preparing the page for printing.

When beforeprint happens

The browser is preparing the page for printing.

You can listen for it using addEventListener(). That keeps event handling separate from HTML attributes such as onclick and works well with modern code organization.

A small working example

<p>Try the relevant browser action described below.</p>
<p id="event-status" role="status">Waiting for beforeprint...</p>
<script>
    const eventTarget = window;
    const eventStatus = document.getElementById("event-status");

    if (eventTarget) {
        eventTarget.addEventListener("beforeprint", (eventDetails) => {
            eventStatus.textContent = "beforeprint event received";
            console.log(eventDetails.type, eventDetails.target);
        });
    }
</script>

Reading the code

The browser listens for beforeprint on the relevant target. When the event occurs, the callback receives eventDetails, updates the status message and logs the event name and target in Developer Tools.

Open the Print dialog; CSS @media print is usually preferable for print appearance.

Some events need a specific browser condition, another tab or window, or a Web Component to reproduce. Read the trigger steps carefully before deciding that an event handler is not working.

Try it in your browser

Open the page, show the Console panel, and follow this test: Open the Print dialog; CSS @media print is usually preferable for print appearance. Then change one thing in the example and observe whether the event still fires.

Common Beginner Mistakes

• Expecting beforeprint to fire without its required user action or browser condition.
• Open the Print dialog; CSS @media print is usually preferable for print appearance.
• Adding repeated event listeners without considering cleanup or unwanted side effects.

Key Takeaways

• beforeprint reports the browser is preparing the page for printing.
• addEventListener("beforeprint", ...) listens for the event on the appropriate target.
• Open the Print dialog; CSS @media print is usually preferable for print appearance.