PHP has no built-in way to render a web page, so the moment you search for "php screenshot website" you hit a fork: install a headless browser stack and drive it from PHP, or skip the browser and call a hosted API over HTTP. This guide covers both honestly, with working code and the gotcha each one hits. First, a trap to clear out of the way.
The trap: imagegrabscreen is not what you want
The top result people find is PHP's imagegrabscreen(). It captures the operating system's desktop screen, the actual pixels on a monitor. It needs a graphical session, only works where a display is attached, and has nothing to do with loading a URL. On a typical headless Linux web server there is no screen to grab. If you want a screenshot of a website from its URL, imagegrabscreen is the wrong function. You need something that renders the page in a browser.
Approach 1: Spatie Browsershot (the standard DIY route)
Browsershot is the most popular PHP screenshot library. It does not render anything itself; it shells out to a Node.js script that drives Puppeteer and a headless Chromium. So the API is clean PHP, but the work happens in a real browser:
