Remove flicker from slow motion video on iPhone

Most indoor lights don't shine steadily. They pulse at twice the mains frequency: 100 times a second on 50 Hz power and 120 times a second on 60 Hz power. At normal frame rates the camera exposes each frame long enough to average those pulses out. At 120 or 240 fps each exposure is shorter than a pulse, so consecutive frames catch the light at different points in its cycle, and slow playback stretches the difference into visible flicker. Read the full explanation.

Yes, in most cases. Flicker is a change in brightness from frame to frame, so software can measure it and even it out without a reshoot. That is what Deflicker does. The limit is detail that was never recorded: areas blown out to white or crushed to black in some frames can't be restored, so very deep flicker may leave slight unevenness. Fusion handles deep flicker best.

Yes. Deflicker works with 240 fps and 120 fps slow-motion clips as well as regular videos. 240 fps footage usually flickers the most, because each frame is exposed for 1/240 of a second or less, shorter than a single pulse of the light.

Not with the on-device fix: it runs entirely on your iPhone and nothing leaves the phone. Fusion runs on our GPUs, so it uploads only the clip you choose to send to Fusion, and that clip is deleted within 24 hours. There is no account and no sign-in.

Fusion is counted in clips. One Fusion clip covers up to 1,000 frames of 1080p video, about 4 seconds of 240 fps slow motion. Longer or higher-resolution videos use more than one, and the app shows how many before you start. Pro Yearly includes 15 Fusion clips a month, Pro Weekly includes 5 a week, and you can add 10 extra Fusion clips for $4.99.

The on-device engine measures brightness across the frame, area by area, and smooths out the pulsing. It is quick, private and right for most clips. Fusion is heavier: it tracks every pixel across frames and rebuilds the light, which helps with deep LED and fluorescent flicker and with parts of the frame that flicker out of step. It runs in the cloud and takes longer.

Subscriptions are handled by Apple. On your iPhone, open Settings, tap your name, then Subscriptions, choose Deflicker Pro and tap Cancel Subscription. Cancel at least 24 hours before the renewal date to avoid the next charge. You keep Pro until the end of the period you have paid for.

Deflicker is an iPhone app and needs iOS 17 or later. It works on videos in your Photos library, whether you filmed them on that iPhone or saved them there from somewhere else.