Touch ID is great, but it isn’t as accurate as we feel it should be, especially under special conditions where your fingers are sweaty or oily. We show you how to improve Touch ID accuracy for specialized, edge cases.
About whining about owning an aging iPhone 4S in every other post here on Cupertino Times, I have finally managed to upgrade to an iPhone 5S (or ‘5s’, as Apple uses it). As you all know, the iPhone 5S comes with the Touch ID sensor and associated software which allows you to unlock the phone, unlock secured apps and log in on the web, and authenticate app purchases. On the iPhone 6, you can even pay for real life items using Apple Pay!
Touch ID uses complex technology. Resting your finger on the steel ring around the Home button activates the circuitry. The Touch ID sensors sends an image of your fingerprint (it also reads beneath the outer layers of your skin for detailed images) to iOS for detection and authentication.
Now, Touch ID is indeed more accurate than most fingerprint scanners out there, but it could be a lot more accurate. Speaking with anecdotal experience, I would say it works about 6 or 7 times out of 10. Under less than ideal conditions, when one’s finger tips are sweaty or oily or have any other fluid-ey material on top, Touch ID essentially refuses to respond, and instead asks you to authenticate using your passcode.
There is a way to improve Touch ID accuracy with sweaty or oily skin. It is surprisingly obvious, and we wondered why we didn’t figure this out before.
Assuming you just tried unlocking your iPhone 5s or 6 or iPad mini 3 / Air 2 with a sweaty or oily fingertip (but failed and entered your passcode), open up Settings > Touch ID & Passcode, and tap on Add A Fingerprint. Now, simply follow the on-screen instructions to your moist fingertip. Touch ID will save this as a separate fingerprint – in addition to the dry copy of the same fingertip – for future authentications.
Using the same techique, you can improve Touch ID accuracy for extremely cold conditions. You can also add a separate fingerprint right after taking a bath to further improve Touch ID accuracy.