Mapbox is creator of GeoJSON format, it is free open source format. Mapbox's GeoJSON viewer are free to use.
https://geojson.io/#map=2/0/20
You can edit polygon and styling and much more. Looks like a browser version of ArcMap. But only have very limit function compare to ArcMap.
Another free tool has No satelite imagery, No street name https://geojson.tools/ ( not recommend )
How to View Geojson by Uploading file to
Option 1 on Esri map
https://transparentgov.net/json2tree/datahub.io/embed/upload_geojson_as_featurelayer.html?clickorhover=click&overlayOpacity=7
Step 1. Upload a geojson file
Step 2. click any polygon, line or point, details info window popup
Option 2 Google Map
View remote GeoJson( URL ) or local GeoJson( xxx.geojson )
https://transparentgov.net/json2tree/gateway/geojson.viewer.html
Upload a geojson file to google map click here
https://transparentgov.net:3200/googlemaps93/upload