I’m working with Puppeteer for web automation and I’m curious about its flexibility. Is there a way to start Puppeteer in headless mode but then make the browser window visible if something goes wrong?
Here’s what I’m thinking:
const browser = await puppeteer.launch({ headless: true });
const page = await browser.newPage();
try {
await page.goto('https://example.com');
// Do some stuff
} catch (error) {
console.error('Oops, something went wrong!');
// Is it possible to make the browser visible here?
// Something like: await browser.setHeadless(false);
}
await browser.close();
Does Puppeteer have any built-in methods to switch modes like this? Or are there any workarounds to achieve similar functionality? I think it would be super helpful for debugging. Thanks for any insights!
As someone who’s worked extensively with Puppeteer, I can tell you that switching from headless to visible mode during runtime isn’t directly supported. However, there’s a workaround that might suit your needs. Instead of launching in headless mode, you can use the ‘defaultViewport’ option to simulate a headless-like environment while still keeping the browser launchable.
Here’s an approach I’ve used:
const browser = await puppeteer.launch({
headless: false,
defaultViewport: null,
args: ['--start-maximized', '--window-position=-32000,-32000']
});
// Your code here
// When you need to make it visible:
await page.evaluate(() => {
window.moveTo(0, 0);
});
This method starts the browser off-screen and brings it into view when needed. It’s not perfect, but it’s the closest I’ve found to achieving what you’re after. Hope this helps!
I’ve encountered this issue before, and while Puppeteer doesn’t offer a direct way to switch from headless to visible mode during runtime, I’ve found a different approach that might work for you.
Instead of trying to switch modes, I’ve had success using a hybrid approach. Launch Puppeteer in non-headless mode, but use the --remote-debugging-port flag to connect to an existing Chrome instance. This way, you can have a visible browser ready to go, but it won’t interfere with your automation unless you need it.
Here’s a basic setup I’ve used:
const browser = await puppeteer.connect({
browserURL: 'http://localhost:9222',
defaultViewport: null,
});
// Your automation code here
// If an error occurs:
if (error) {
console.error('Error detected, check the browser');
// The browser window is already open, so you can interact with it directly
}
This method gives you the flexibility to see what’s happening when needed, without the overhead of always running in visible mode. It’s been a game-changer for my debugging process.
hey pete, i’ve messed with this before. sadly, no direct way to switch mid-run but here’s a trick: launch non-headless, use ‘–window-size=1,1’ arg to make it tiny. when u need visibility, just resize:
but here’s a trick: launch non-headless, use ‘–window-size=1,1’ arg to make it tiny. when u need visibility, just resize: