Why Installing an Extension Is the Wrong Default
An extension only works on the device it's installed on, in the browser it's installed in, for the tab you're currently looking at. That's a hard requirement most people checking a tech stack don't actually need — they have a URL, often for a site they have no reason to visit themselves, and want an answer. Installing a browser extension, granting it page-read permissions, and navigating to the target site first is three steps where one paste should do.
It also simply doesn't work in a lot of real situations: locked-down work laptops that block extension installs by IT policy, mobile browsers where extensions mostly don't exist, and any case where you want to check a site without the friction of opening it yourself.
What Checking Ten Sites Actually Looks Like With Each Approach
With an extension, checking ten competitor sites means opening ten tabs and clicking the extension icon ten separate times — there's no batch mode, no paste-a-list workflow. With a URL-paste tool, it's ten pastes, no navigation required, and nothing to install first. For the single-site, occasional-use case the gap barely matters; for anyone doing repeated competitive research, it's the difference between a five-minute task and a thirty-second one.
A URL-based tool also removes any question of extension permissions — there's nothing installed in your browser with standing access to every page you visit, since the tool only ever sees the specific URL you choose to submit.
The One Real Tradeoff, and Why It Rarely Matters
There's one genuine technical difference worth naming honestly: an extension observes the page exactly as the browser renders it, including content that only appears after JavaScript executes, while a URL-paste tool reads the initial server response. For the overwhelming majority of sites — where CMS, hosting, CDN, and analytics signals are present in that initial response — this makes no practical difference to the result.
It only matters for a narrow case: auditing a heavily JavaScript-rendered single-page application where the entire interface builds client-side. That's a small slice of the sites anyone is actually checking, and not a reason to install and maintain a browser extension for routine lookups.