Life & fun · September 18, 2017
SentinelJS – Detect new DOM nodes using CSS selectors
Detect new DOM nodes using CSS selectors (650 bytes) - amorey/sentineljs
SentinelJS – Detect new DOM nodes using CSS selectors launched on September 18, 2017 with 90 votes, #486 of 3,072 launches that month and more than 90% of that year's launches. The site was still online in September 2026, 9 years on.
In plain words
SentinelJS is a JavaScript library that detects when new DOM nodes matching specified CSS selectors are added to a webpage. It works by monitoring the document for changes and triggering callbacks whenever elements matching user-defined selectors appear. The tool is useful for developers building dynamic websites or browser extensions who need to respond automatically to newly created page elements without manually polling the DOM.
written from the facts on this page · September 2026
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