Why CSS selectors break and how I created StableHTMLFinder to analyze DOM stability
If you've ever written CSS selectors for browser automation, page parsing, or blocking unwanted elements, you've likely encountered a situation where: yesterday the selector worked, but today it stopped finding the right element. The reason is often not in the selector error, but in the page itself. Modern sites actively use dynamically generated classes, changing attributes,…
A developer has created a Chrome extension called StableHTMLFinder, which helps identify stable parts of a webpage's DOM (Document Object Model) that remain unchanged across multiple page reloads. This was motivated by the challenge of writing reliable CSS selectors for automating browser tasks, parsing pages, or blocking unwanted elements, as modern websites often use dynamic content.
The extension generates a "stability map" of the webpage, highlighting elements and attributes that remain stable, allowing users to easily find reliable selectors for tasks such as blocking unwanted content. The developer, who also created the BlockIt extension, was inspired to create StableHTMLFinder after encountering difficulties with dynamic content while working on BlockIt in 2026.
Written by urgent.news from Dev.to's report — not a translation of it. Machine-written — may contain errors; check the original before relying on it.
