livepreview

Livepreview, commonly written as live preview and in some software as LivePreview, is a feature that renders a representation of content or output while edits are being made. The goal is to let users see the effect of changes in near real time without exporting, building, or switching to another tool. The concept is widely used across software development, document authoring, and content creation.

In web development and design, live preview updates a rendered HTML/CSS/JS view as code is edited. This is implemented with local development servers, file watchers, and mechanisms such as hot module replacement or WebSocket push. Editors may present a split view, with source on one side and the live output on the other, or an embedded preview pane. In Markdown, LaTeX, or WYSIWYG editors, live previews show formatted output as you type.

Benefits include faster feedback, reduced context switching, and better alignment between author intent and final presentation. Limitations include possible latency, discrepancies between the preview and final rendering across browsers or devices, performance overhead, and security considerations when running embedded code or loading remote resources.

While the core idea is simple, implementations vary by platform and workflow. Some environments emphasize instantaneous updates, while others focus on deterministic builds for production parity. The term live preview is used variably, and related concepts include live reload, hot reload, and live rendering.