Four to six digits stand between most iPhone users’ personal data and the prying eyes of snoops, criminals, and investigators. To access records stored within, a hacker has little choice but to barrage a lock screen with possible PINs until the electronic tumblers click. Problematically, these “brute-force” attempts trigger built-in time delays—and potential data wipes.

A court recently ordered Apple aapl to develop an operating system stripped of such barriers to aid an FBI investigation into the December shootings in San Bernardino, Calif.  The company has emphatically objected for fear that the tool could be abused. Depending on the strength of a user’s passcode, however, anyone’s iPhone could easily remain a black box.

Use the tool below to test how long on average it would take some to crack various passcodes in a world where a crippled version of Apple’s software—of the sort that law enforcement desires—hypothetically got out into the wild. Though Fortune doesn’t store any of the entered information, we do not advise punching in your actual passcode. Who knows what key-loggers or man-in-the-middle attackers might be lurking on your machine or network?

Interactive by Analee Kasudia and Stacy Jones

Want to boost your security? Consider increasing the number (or type) of characters required to unlock your handset. Here are 10 simple steps for anyone running iOS 9, the latest version of Apple’s operating system. Just first make sure there aren’t any people (or cameras!) peering over your shoulder.

1.) Unlock your phone.
2.) Tap the “Settings” icon.
3.) Tap “Touch ID & Passcode” or “Passcode.”
4.) Enter current passcode.
5.) Tap “Change Passcode.”
6.) Enter current passcode.
7.) Tap “Passcode Options.”
8.) Tap “Custom Alphanumeric Code.”
9.) Create your new passcode using a combination of numbers, case sensitive letters, and special characters.
10.) Celebrate your newfound security! And remember this passcode!

For more, here’s a handy breakdown of how long on average it might take to break a passcode:

CHA.03.15.16.featured Click to enlarge.Source: Apple; Dan Guido, CEO, Trail of Bits

A version of this article appears in the March 15, 2016 issue of Fortune.