The export command provided by Marp for VS Code, except HTML output, launches the browser in the background, fetches resources, renders slide pages, and converts to the specified file type. If the remote server is not responding for a long time due to low network bandwidth, firewalls, and other possible reasons, the export command may timeout. (e.g. Web fonts, emojis, and KaTeX math styles may be fetched from the remote server)

Currently Marp for VS Code is not providing a preference for the custom timeout duration, and only can set via the environment value for debug purpose. Please refer to https://github.com/orgs/marp-team/discussions/225#discussioncomment-4420584.

By using Marp CLI, you can easily set the custom timeout duration through --browser-timeout option. A following example is to set the timeout duration as 120 seconds (2 minutes).

marp --browser-timeout 120 slide.md