I was wondering, which browsers have a sandbox? I believe chrome does
I am hoping all of the major ones have that capability soon...
Chrome and IE both do. IE's can be improved by using the "enhanced protection mode (EPM)" in the advanced tab of internet options (this uses AppContainers on Windows 8+) and the 64-bit processes for EPM. Chrome's sandbox is actually better on linux (chroot + seccomp among other things).
Firefox does not and I am unsure about Opera. Hopefully with the feature to leverage multiple processes Firefox will also add some sort of sandbox although I don't think that's the original intention of using multiple processes (which is stability, e.g. a tab crashes the browser won't).
You can enhance the mitigation in all browsers with EMET (not limited to just browsers). Importing the popular software profile after installing with recommended defaults includes all of the above browsers.