Diffence node in two broswer when open website?

I created a file upload website using js-ipfs, but the file is not shared after the address is opened in different browsers. For example, I opened it on Chrome and uploaded the file and then opened it in Firefox and found that the MFS did not exist.
and I use IPFS.create({ repo:"/var/ipfs/"})
but I can not find the path in my computer?
Can I create a node with an same config so that people can upload file to one node on difference platform