There're many reasons you might want to browse anonymously which can be accomplished by using [Tor](https://www.torproject.org). The setup instructions on Tor's website are quite scattered and outdated so here're some steps to setup Tor on OS X with a simple automated script at the end.
I'm using OS X Yosemite (10.10) for the following instructions but it should work on almost any OS X version.
## Tor Browser
The most simple way to surf anonymously with Tor is to just grab the [Tor Browser](https://www.torproject.org/projects/torbrowser.html.en) bundle.
But it's based on a super old version of Firefox. And there might be more you want to do anonymously on your machine than just browsing the web, like accessing resources via the Terminal or any other app. Or just use the browser you're used to.
For this you need to have Tor installed on your system and additionally set specific Proxy values in your network preferences after you've started Tor.
## Install Tor
Contrary to the weirdly outdated [install instructions on Tor's website](https://www.torproject.org/docs/tor-doc-osx.html.en) (hey, remember Macports?), installing Tor on Mac OS X is super simple with [Homebrew](http://brew.sh).
In order for all your system traffic being routed through Tor you need to adjust your system's network proxy settings which you can either do visually in the System Preferences or programmatically via OS X's builtin `networksetup`.
## Set network proxy settings via System Preferences
You can do this under System Preferences > Network and creating a specific Tor network location for it:
1. From Location dropdown at the top, select Edit Locations...
2. Create a new location by hitting the plus button and name it *Tor*. Hitting Done will select the new location which is now ready to be configured
4. Go to Advanced > Proxies and activate *SOCKS Proxy* and add those values:
- *SOCKS proxy server*: `localhost`
- *Port*: `9050`
After hitting *OK*&*Apply* at the initial network screen, you can easily switch to this newly created location from your menu bar under > Location whenever you start up Tor.
Switching to the Tor location routes all network traffic on your system through Tor. Note that you have to repeat those steps for every other network interface if you use, say, Wi-Fi and Ethernet interchangeably.
## All in one go: start Tor & set network proxy settings automatically
When you're already in the Terminal to start up Tor, additionally setting the network settings invloves a lot of fiddling around. Ain't nobody got time for that.
Thankfully OS X provides a way to programmatically set those proxy values via the `networksetup` utility. I've found a [nice script](http://leonid.shevtsov.me/en/an-easy-way-to-use-tor-on-os-x) for this but running it opened multiple admin password prompts. So I extended it a bit to make it more user friendly.
In a nutshell, this shell script asks you for your admin password upfront, starts up Tor, and sets all required proxy network settings automatically:
```bash
#!/usr/bin/env bash
# 'Wi-Fi' or 'Ethernet' or 'Display Ethernet'
INTERFACE=Wi-Fi
# Ask for the administrator password upfront
sudo -v
# Keep-alive: update existing `sudo` time stamp until finished
while true; do sudo -n true; sleep 60; kill -0 "$$" || exit; done 2>/dev/null &
Save this script under something like `tor.sh` in one of your sourced `bin` folders, make it executable with `chmod + x` and use it as a replacement for the general `tor` command. So you can just run
