HTML—the Most Difficult Programming Language in the World

Years ago, the web development community discussed and declared on Twitter that HTML was not just a document language, but a programming language.

Meanwhile, virtually no HTML page is error-free. In HTML parlance, almost no page is conformant, compliant, valid, or “validates.” (Cf. validation data from 2021 through 2025.)

If HTML is a programming language, yet virtually no one writes error-free HTML code, there can be only one conclusion:

HTML is the most difficult programming language in the world.

This is tongue-in-cheek, but the underlying point isn't: If you’re a professional who puts HTML on your resume, ship valid HTML. This is the minimum to be expected of our work, even when our manager or our client doesn’t ask for it. It’s not that hard.