Confirm structural requirements
The iframe must be present in markup, and its src should point to a playable document rather than a static image. If the attribute is empty, check for alternate data attributes and normalise them to a real URL.
AutoEmbedGames parses src, data-src, data-game, and similar fields. When a valid match is found, the system rebuilds the iframe tag and rejects image-only endpoints.
Validate document responses
We fetch each candidate URL, inspecting the payload for <html>, canvas elements, or executable scripts. Any response returning 4xx/5xx or a pure binary object is flagged and removed from the list of approved embeds.
When you need extra assurance, open the URL in a separate tab and use DevTools network logs to confirm that the document successfully loads required JavaScript, WebGL, or Unity assets.