Can I switch Chrome WebDriver from headless to visible mode during runtime

Other Questions Headless Browser
1

I’m working with Selenium and Chrome WebDriver in Python. I started my browser session in headless mode by adding this option:

browser_options.add_argument("--headless")

Then I initialize the driver like this:

driver = webdriver.Chrome(service=Service("./chromedriver"), options=browser_options)

Now I need to make the browser window show up when certain conditions are triggered in my script. I tried to remove the headless flag like this:

browser_options.arguments.remove("--headless")

But the browser stays invisible. Is there a way to change from headless to visible mode without restarting the entire WebDriver session?

2

Nope, Chrome WebDriver won’t let you do this. Headless mode gets locked in when the browser starts up. I hit the same problem debugging automation scripts when I suddenly needed to see what was happening on screen. My workaround: save the session state (cookies, current URL, form data), kill the driver, and restart it in visible mode. Not pretty, but it works. State restoration takes a few seconds if you’re organized about it. Some devs use separate debug builds that start visible, but that’s useless when you need the switch to happen during runtime.

3

Nope, you can’t switch Chrome WebDriver from headless to visible while it’s running. Once you launch the browser with headless mode, that setting is locked in and can’t be changed. The headless flag gets processed when the browser starts up, not while it’s running. I hit this same issue when building test scripts that needed to show the browser for debugging. Your only option is to kill the current driver and start a new one without the headless flag. You can save your current state first - grab cookies, local storage, or the current URL before restarting the driver. Yeah, it adds overhead, but that’s how it works since the display mode is tied to how the browser process starts.

4

Nope, can’t do it once Chrome’s running. The --headless flag gets locked in at startup - I’ve tried. My workaround is running two drivers: keep one headless for normal stuff, then switch to the visible one when I need to debug. It’s messy but beats restarting everything.