Download websites that use Less

About Less

Detecting Less on a live site usually means something more specific than the tool's own description suggests. Less is a CSS preprocessor, and in a modern workflow preprocessing happens at build time and leaves nothing behind for a crawler to find. When we can see it, the site is shipping the browser-side compiler to visitors and letting their browser do the work, which was an accepted practice around 2009 and has not been one for a long time.

So the detection functions as a date stamp. A site compiling stylesheets in the browser was most likely built during the years when Bootstrap's own stylesheets were written in this language, and it has been carried forward without a rebuild ever since. Presence correlates with a template bought rather than commissioned, a theme that has never been re-exported, and a front end nobody has opened in years. The practice also carries a performance cost no current developer would accept, because the page cannot be styled until a JavaScript file has downloaded, parsed and generated the stylesheet.

As of September 2026 the browser-side compiler is present on 107,202 sites, filed under Miscellaneous because what our crawler matches is the script rather than the language it processes. United States accounts for 39,122 and .com leads the domain breakdown, though for a signal about build practice the country split matters less than the age of the sites carrying it.

Less is open source under the Apache 2.0 license, so nothing in this population reflects a purchase and the vendor field is empty for a reason. There is no company to sell to and no renewal cycle to track. We publish no version distribution either, because the browser build is usually referenced from a shared path or bundled without a readable version marker. The undercount deserves stating plainly: every site that compiles properly at build time is invisible to us, and those are the sites still actively maintained. What remains in the data is the tail that never rebuilt.

The tail has buyers. Agencies selling redesigns want lists of sites that demonstrably have not been touched, performance tooling wants sites with a render-blocking problem that can be measured before and after, and security teams want inventories of old front-end dependencies loaded from third-party origins. Each of those cases needs a population rather than a verdict on one domain, and each needs it joined to country, TLD and the rest of the stack on the same site. A lookup answers a yes or no question about a single address. The download answers how many, where, and alongside what.