A support table became the thing people argued from

Can I Use turned browser support into a citable artefact, which changed technical arguments from opinion into a shared reference.

Can I Use turned browser support into a citable artefact

Before Can I Use existed, the question of whether a CSS property or JavaScript API was safe to use in production was settled by reputation. Senior developers remembered which browser had broken what, junior ones asked on forums, and the answer depended heavily on who you asked and when they had last checked. Alexis Deveria launched Can I Use in 2010 as a straightforward grid of features against browsers, each cell coloured green, yellow, or red. The simplicity was the point.

What changed was not the underlying data — browser compatibility tables had existed in documentation form for years, and MDN had been accumulating them since the mid-2000s — but the framing. Can I Use presented support as a percentage of current web users, calculated against real-world browser usage statistics. That number gave engineers something to put in a ticket or a Slack thread that their manager could not easily dismiss. "Ninety-three percent global support" is an argument; "most browsers probably handle this" is not.

The site's influence on how specifications moved forward was less obvious but just as real. TC39, the committee responsible for evolving JavaScript, operates on a stage process partly because shipping a feature too early, before browsers converge on an implementation, creates exactly the kind of fragmented support that shows up as a red cell. Developers watching Can I Use could see in real time which proposals were moving in step and which were stranded at partial support across half the market. The table did not set the standard, but it made the distance between a spec and a usable feature legible at a glance.

For a period roughly spanning 2012 to 2018, Can I Use was a routine citation in arguments about whether to use native features or lean on a polyfill to paper over the gap. Those arguments had weight because the DOM APIs themselves had converged unevenly, and the scars were recent enough that teams had learned not to assume browser parity just because a spec existed. A support table that told you Firefox was behind by two versions was more useful than a specification that told you the feature was finalized.

Can I Use is now maintained as an open-source project with data drawn from multiple sources, including the HTTP Archive's crawls and browser vendor release notes. The coloured grid that Deveria built has become so standard a reference that browser vendors themselves track it to see how their own support coverage reads to developers — which is, in its quiet way, a significant reversal of the original direction of authority.