> For the complete documentation index, see [llms.txt](https://docs.umbraco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.umbraco.com/sustainability-best-practices/frontend/lazy-load-resources.md). # Lazyload resources It’s possible that the assets that are within the context of your web page are not even visible to the user. It's therefore wasteful to load these resources. A technique is to add a lazy loading flag to images, videos, or iframes that are `below the fold`. They are only loaded when they enter the browser's viewport. We can further expand this technique by loading assets based on user interaction. For example, if the video is visible but the user hasn't chosen to play it, there's no need to load its resources. By using `onclick` events, we can load only what’s needed when the user clicks the play button. This approach can also be applied to implementations like chatbots or external maps. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.umbraco.com/sustainability-best-practices/frontend/lazy-load-resources.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.