Questions, bugs, or a swing that won’t track.
Strobe is a small, independent iPhone app for golf swing analysis: record or import a swing, replay it frame by frame, get automatic body tracking and metrics, and optionally a written read from an AI provider you connect yourself. Everything is computed on the device.
Frequently asked
How should I film a swing?
Record in slow motion. On iPhone that means the Slo-mo mode in Camera (240fps at 1080p gives the cleanest frame stepping), or recording inside Strobe, which asks the camera for the highest rate it supports. A 30fps clip will import and analyse, but a golf downswing lasts about a quarter of a second — at 30fps that is roughly seven frames, and neither you nor the tracker can see much in seven frames.
Beyond frame rate: film in good light, put the phone on something steady, and frame the whole body with a little room above the club at the top. Down-the-line (behind you, looking at the target) and face-on are both understood.
Why does my clip say tracking was poor?
Body tracking needs to see you. Low light, a busy background, clothing close in colour to the background, a camera that moves mid-swing, or a body partly out of frame will all reduce confidence. When confidence drops, Strobe says so on the clip rather than quietly reporting numbers it does not trust. Re-film with more light and a steadier phone and it usually clears up.
What does “estimated” mean on a metric?
A single phone camera measures pixels, not physics. Anything that requires real-world scale or depth — club head speed, for instance — is derived from tracked positions plus assumptions about club length and your distance from the camera. Those numbers are marked as estimates and shown as a range instead of one confident figure.
Treat estimates as relative, not absolute: the useful question is whether today’s swing is faster or smoother than last week’s, not whether the number matches a launch monitor. Metrics that come straight from the frames — tempo ratio, joint angles, the frame each phase starts on — are not estimates and are not labelled that way.
How do I set up AI coaching?
Coaching is off until you connect an account of your own. In Strobe, open Settings → Coach → Coach setup and follow the three steps: what the coach runs on, getting a key from Anthropic, OpenAI or Google, and pasting it in to verify. The key is stored in the iOS Keychain, and from then on the app talks to that provider directly from your phone.
The coach setup guide walks through it with all three providers’ consoles step by step. Remove the key at any time in the same screen and coaching switches off.
Does my video get uploaded anywhere?
No. Video is recorded, stored and analysed on your iPhone and is never uploaded — not to us, not to your AI provider. The only thing that leaves the device is what you send yourself with the share sheet, and, if you turned coaching on, the metrics and key frames described above. The full detail is in the privacy policy.
Can I get my swings out of the app?
Yes. Any clip exports as an annotated slow-motion video through the standard share sheet, and a whole session exports as a single file containing the videos, the analysis and any coaching, which another copy of Strobe can import intact. Deleting the app deletes everything it stored.
What do I need to run it?
iPhone · iOS 26 or later. High-frame-rate capture and on-device tracking depend on the camera and Neural Engine, so a recent iPhone gets noticeably better results — but you can import and analyse slow-motion clips filmed on any camera.
Is this coaching?
No. Strobe gives you swing feedback from video estimates. It is not professional instruction and not medical advice. If something hurts, stop, and talk to a person.
Something is broken
Email stathis.alexander@gmail.com and say what you did, what happened, and which iPhone and iOS version you are on. If it involves one particular swing, exporting that session and attaching it makes it far easier to reproduce.