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It's a Google Search feature [0]. Add "cache:" in front of the URL you search on Google to try and view the cached version.

Since most browsers nowadays implement an "omnibar" with Google as the default search provider, it appears seamless and performs the redirect.

Because they also control the browser, only works in chrome

It works in Firefox too, but I guess that's because I have Google set to my default search engine. Good trick.

It works for me in Safari macOS Sierra

I assume it is built into Chrome and is just a redirect.