Sork had a map exporter tool which allow you to edit BrowserQuest's maps.
Here's how to process :
1. Download the BrowserQuest's source code : HERE.
2. Download Tiled Editor software : Windows / Mac
3. From the BrowserQuest's zip, open this folder : mozilla-BrowserQuest-af32d24 then go here : \tools\maps\tmx.
4. Right click on map.tmx file and choose "Tiletmx edit".
Now you can edit the BrowserQuest's maps.
Here's the official tutorial : https://github.com/mozilla/BrowserQuest/tree/master/tools/maps
Here's how to process :
1. Download the BrowserQuest's source code : HERE.
2. Download Tiled Editor software : Windows / Mac
3. From the BrowserQuest's zip, open this folder : mozilla-BrowserQuest-af32d24 then go here : \tools\maps\tmx.
4. Right click on map.tmx file and choose "Tiletmx edit".
Now you can edit the BrowserQuest's maps.
Here's the official tutorial : https://github.com/mozilla/BrowserQuest/tree/master/tools/maps