Sideloading f.lux

f.lux is no longer available here

November 12, 2015, 1PM PST

Apple has contacted us to say that the f.lux for iOS download (previously available on this page) is in violation of the Developer Program Agreement, so this method of install is no longer available.

We understood that the new Xcode signing was designed to allow such use, but Apple has indicated that this should not continue.

The demand for f.lux on mobile devices is at an all-time high:

  • This page was visited 176,000 times in its first 24 hours
  • In that time, this download was featured on Product Hunt, LifeHacker, BGR , 9to5Mac , TechCrunch, The Next Web, and many more.
  • As well, the f.lux desktop software has been downloaded more than 15M times to date

It is proven that screens can negatively influence sleep, and we believe that f.lux makes a significant improvement, as it mirrors very closely the research on blocking blue light before bed. But as we’ve discovered, it is even difficult to conduct basic research in this area, because so many people today use mobile devices (with closed APIs) right before bed.

Sleep health is connected in the literature with obesity, diabetes, accidents, cancer, and mood disorders.

Technology and devices that know more about our bodies could make a major impact on health and wellness, and these are the reasons why we work on it every day.

This is why f.lux is free.

f.lux cannot ship an iOS App using the Documented APIs, because the APIs we use are not there. In the last 5 years, we have had numerous conversations with Apple about our product and what would be required to make it work with iOS.

We respect Apple’s products enormously, and we urge Apple to allow work like ours to continue through Documented APIs.

Feedback to Apple can be written here.

Thank you for your love and support.

—Michael and Lorna

Sideloading f.lux on iOS with Xcode 7

In Xcode 7, you can install apps directly to your iOS device with a free account from Apple. So we decided to make a beta version of f.lux for people to try.

It’s a few more steps than installing the app store, but there are plenty of harder things even on Pinterest. So, here’s how to get f.lux installed on your iOS device.

Download f.lux for iOS
for use with Xcode 7


  • Mac, OSX 10.10 or greater
  • 1 installed version of Xcode 7
  • 1 Developer account (use your AppleID)
  • 1 Download, f.lux for iOS, unzipped


First, mix the build ingredients together. Batter may be slightly lumpy.

  1. Open the “iflux.xcodeproj” project in Xcode
  2. Open Xcode > Preferences > Accounts and enter your iCloud or developer credentials
  3. Under Targets > iflux > General > Identity, add a word to the end of the Bundle Identifier to make it a unique name
  4. In the same place, under Identity > Team, select your iCloud account or Developer profile

While the batter chills, connect your iPhone or iPad and load the iflux build:

  1. From the Xcode Product menu, choose Destination and select your iOS device (f.lux doesn’t work in a Simulator)
  2. Push Cmd-R when you’re ready to have f.lux
  3. When you first run, you’ll be prompted to open Settings > General > Profile on your device, and trust your developer account
  4. Run again, and allow location and notifications (things don’t work so well without both of these)

By loading an app this way, there are no automatic updates or bug fixes, so this version does a daily update check. If one is available, a message will appear at the bottom of the app, so you can stay up to date when we make fixes.

We welcome your feedback - this is a beta release so please let us know if you find any issues or have feature requests. Visit our forum to discuss.


Q: Why is my screen waking up?

A: f.lux has to wake up your screen to make changes: * The best way we know to do this is to send notifications (which is why you’ll see a lot of them). * If you disallow notifications (or have “do not disturb” turned on), it will instead do this by asking for a device unlock, which wakes up the screen for quite a while. This is not a security risk or anything to be worried about. * If you allow notifications and make “do not disturb” hours reflect your bedtime, it will be quite a bit less annoying.

Q: Why is my screen locked at 1900K? I don’t want it this dark.

A: Because we added the bedtime mode without really finishing the UI to customize it! So if you don’t like that, or if you prefer the classic/Windows sunrise/sunset, just change the wake time setting to “Dawn” until we make a better UI. “Bedtime mode” overall is supposed to look like a candle while you’re sleeping so you can use your device in the middle of the night, if you have to.


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