View local GeoJSON
Download the example Average Wind Speeds GeoJSON. Instead of uploading the file to a server and reading it from there, the browser directly accesses the file locally, eliminating the need for any network transfer. If you wish to write to the file that has been opened, you can refer to the following example that utilizes the File System Access API: View local GeoJSON (experimental).
Related examples
An extension of MapLibre GL JS