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I use Google quite a bit when conjuring up R projects, whether it be in a lazy pursuit of a PDF vignette or to find a package or function to fit a niche need. Inevitably, I’ll do something like this (yeah, I’m still on a mapping kick) and the first (and best) results will come back with https://cran.r-project.org/-prefixed URLs. If all this works, what’s the problem? Well, the main CRAN site is, without mincing words, slow much of the time. The switch to https on it (and it’s mostly-academic mirrors) has introduced noticeable delays.

Now, these aren’t productivity-crushing delays, but (a) why wait if you don’t have to; and, (b) why not spread the load to a whole server farm dedicated to ensuring fast delivery of content? I was going to write a Chrome extension specifically for this, but I kinda figured this was a solved problem, and it is!

From the plethora of options in the Chrome Store, I grabbed Switcheroo Redirector because (a) it has a decent user base and rating; (b) it’s not super-complex to use; and, (c) the source is on github and closely matches what’s in the actual installed extension (some extensions are tricksy/evil and you can even build your own with the source vs trust the Chrome Store one).

So, go install it and come back. We’ll wait.

OK, you back? Good. Let’s continue. You should have a Switcheroo icon near your location bar. Select it and you should see a popup like this:

I’ve already made the entry, but you just need to tell the app to substitute all URL occurrences of cran.r-project.org with cran.rstudio.com when Chrome is trying to load a URL.

Now, when you click one of those links in the above example, it will go (speedily!) to the RStudio CRAN mirror server farm.

Once nice (to security freaks like me) feature is that if you have one of the Switcheroo links open in a new tab (i.e. not directly/immediately visible to you) it will let you know that something is happening out of the ordinary:

This is a tiny (and good) price to pay to know you’re not being whacked by a bad plugin.

If you have another preference (or have suggestions for Safari or Firefox) please drop a note in the comments so others can benefit from your experience!