Copy and paste following sample URL ( or your arcgis rest api endpoint URL ) next to 'let's go' button, then click 'enter' key or 'let's go' button
1). Arcgis Online ( Palm Springs, CA ):
https://services.arcgis.com/f48yV21HSEYeCYMI/arcgis/rest/services
2). Arcgis Portal ( HRSA ):
https://gisportal.hrsa.gov/server/rest/services
3). Arcgis Server ( USGS ):
https://gis.usgs.gov/padus/rest/services
4). Arcgis Server ( La Quinta, CA ):
https://gis.la-quinta.org/arcgis/rest/services
Click the following link to open a bigger page
Simple Folder
https://transparentgov.net/json2tree/esri/server/folder.html
Advanced Folder
https://transparentgov.net/json2tree/esri/server2/folder.html
Advanced Layer
https://transparentgov.net/json2tree/esri/server2/searchLayer.html?url=&org=&cross=default&timeout=10000&filter_by=
Simple Layer
https://transparentgov.net/json2tree/esri/server/searchLayer.html?url=&org=&cross=default&timeout=10000&filter_by=
Advanced MapServer
https://transparentgov.net/json2tree/esri/server2/searchMapServer.html?url=&org=&cross=default&timeout=10000&filter_by=
Simple MapServer
https://transparentgov.net/json2tree/esri/server/searchMapServer.html?url=&org=&cross=default&timeout=10000&filter_by=
How to use
https://transparentgov.net/cleargov1/1149/how-to-explore-arcgis-rest-api-endpoint-army-corps-engineers