> For the complete documentation index, see [llms.txt](https://docs.screendesk.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.screendesk.io/screen-recorder/record-and-capture/instant-replay/performance.md). # Performance How Instant Replay stays fast, and what happens on heavy pages. Instant Replay keeps a short rolling buffer of page changes in your browser. Its impact depends on how much the page changes. ## Enable only the websites you need Instant Replay is off by default for each website. Enable a website through **Enable on this site** or **Settings → Manage Websites → Always Enabled Sites**. Busy dashboards, large documents, and pages with frequent visual updates can require more CPU and memory. Remove the website from Always Enabled Sites or block it if capture affects your work. ## A rolling buffer Screendesk keeps about two minutes of recent page activity, replacing older activity as you continue using the page. It uses page snapshots and incremental updates rather than recording every screen pixel. Canvas content and cross-origin iframe content are not recorded by Instant Replay. ## Website rule priority 1. **Blocked Sites** disables replay. 2. **Always Enabled Sites** enables replay on supported pages. 3. Other websites stay disabled. See [Website management](/screen-recorder/settings/website-management.md) to change these rules. --- # 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 dynamically by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.screendesk.io/screen-recorder/record-and-capture/instant-replay/performance.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 `build a script that syncs our docs to a CMS` 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.