Devices & troubleshooting FAQ

On a phone you can upload a clip from your camera roll, or record with RecordAssist, the guided recorder, once you have a free account. Because the analysis happens on your device, an older phone takes longer than a new one.

If analysis is slow or stalls, open Advanced capture settings in Motion Lab and set Tracking accuracy to Fast, which is meant for older phones.

See which browsers work for what your browser needs.

• Analysing an uploaded clip: the browser has to decode the video and download and run the body-tracking model. It uses the graphics chip where it can and a slower fallback where it cannot.
• Recording with RecordAssist: camera access over a secure (https) connection, plus in-browser recording. Without recording support you can still upload a clip.
• Live body tracking while you record: WebGL graphics support. Without it, RecordAssist falls back to manual framing guides.
• Spoken guidance: speech support in the browser. Without it, on-screen captions still guide you.

Private or incognito windows can block storage on the device, so analyses and kept clips may not survive closing the window.

If one browser keeps failing on the same clip, try another browser before re-filming anything — the problem may be the browser, not the video.

What probably happened: an earlier prompt was answered with Block, so the browser now refuses without asking. If the browser never asks at all, check that the browser app itself is allowed to use the camera in your device settings.

• "Camera access was blocked" — allow it in site settings, then try again.
• "Camera is in use" — another app or tab has the camera; close it.
• "No camera found" — this device has no camera the browser can use; switch to a phone.
• "Guided recording isn't available here" — camera access needs a secure (https) connection and a browser that exposes the camera.

You never need the in-app camera to get an analysis: film with your phone's normal camera app and upload the clip to Motion Lab. RecordAssist only uses the camera while its screen is open, and the live preview is never uploaded or saved.

What probably happened: Motion Lab looks for a person in the frames it samples. Found in fewer than about half of them, the reads are partial and lower-confidence. Found in almost none, the capture is graded not defensible and anything it keeps is heavily capped. Found in none at all, there is no athlete in the evidence, so it withholds the results instead of guessing.

What to try with the same clip: trim it to the rep so the samples land on you rather than on an empty court or bay, and run it again. A second run also clears the engine and frame-reading failures described above. Re-record when the results say your body could not be reliably found, and next time:

• fill about half the frame height, head to feet, with a little room above and below;
• film in even light that faces you, not from behind you;
• keep only yourself in the shot, with the phone propped steady.

Where next: getting your whole body in frame and lighting and background.

Golf: automatic clubhead tracking is not reliable enough yet to draw the club's path by itself, so Motion Lab traces your hands. To trace the clubhead, open the video in your results, choose Mark clubhead and tap the head on a few clear frames through the swing — your marks become the trace. See club path versus the clubhead trace.

Other sports: where the bat, racquet or paddle head was picked out in the frames, the trace follows it and says in how many analysed frames it was seen. Where it never was, the trace follows your hands, or is labelled as projected out along your forearm. Either way, treat its shape as directional.

What helps: keep the whole implement in frame through the finish, film at 60 fps so it does not blur through contact, and pick a background it stands out against. Your body-position reads come from the tracked joints, so they still stand when no path is drawn.

Capture quality sets a ceiling: a Usable clip tops out at 70%, a Limited one at 45% and a Difficult capture at 30%. No amount of analysis lifts a read above what its footage supports.

The sport sets a ceiling too. Golf has the deepest analysis; the other sports get directional reads with a lower maximum, so a perfect clip in those sports still stops below what a golf clip can reach. See why confidence is capped by sport.

1. Read the limiter named with your result.
2. Apply the fix it lists — the capture changes are specific to that clip.
3. Re-film from the same spot, so the new clip can be compared with the old one.

Low confidence does not mean the finding is wrong. It means treat it as a lead to check rather than a conclusion — see what confidence means.

• Fast motion — between analysed frames the overlay is filled in from the nearest ones, so it can lag a quick arm, club or racquet.
• Hidden joints — an arm behind your body or a foot out of shot is placed with less certainty.
• Blur and low light — soft frames make joints jitter.
• Someone else in frame — the tracking can jump to the other person.

What helps: a steady camera, 60 fps, even light and only you in frame all tighten it. Small offsets are normal for positions read from one camera; large, consistent ones are worth a re-film.

If the overlay is badly off all the way through a clean, well-lit clip, tell us the sport, motion and device you used.

• The engine couldn't start — a one-time download it needs did not complete. Check your connection and run the analysis again; your video still never leaves your device.
• The device couldn't read any frames — run it again, and if it fails twice, try another browser on the same clip before re-filming.
• A step took too long — try a shorter clip, or set Tracking accuracy to Fast under Advanced capture settings.
• The page was closed or reloaded — open Motion Lab again and choose "Continue with this clip" under "We kept your last clip".

Re-record when the failure is about the footage: no athlete could be found, or the message names darkness, cropping or no clear motion. The "try this" box on the error screen gives the specific fix.

No usable clip right now? The error screen also offers a starter plan from three quick questions, labelled as self-reported rather than measured from video. If it keeps failing, contact us.

• The 20-second limit — a cap, not a fault. Tap Record when you are nearly set and let the countdown take you into the rep.
• "Recording stopped unexpectedly" — the recorder failed. Try again; if it keeps happening, use your camera app and upload the clip instead.
• "This browser can't record video" — in-browser recording is not supported here. Filming with the camera app and uploading works just as well for analysis.

Finished takes are saved on your device before analysis, so a reload does not lose them — Motion Lab offers the take back as your last clip.

Want more of your practice on camera? Record separate takes of the reps you care about; see how long a clip should be.

• Not signed in — without an account, results run from the summary to the main issue. Creating a free account or signing in brings you back to the same place.
• No read at all — when no person could be tracked anywhere in the clip, or the analysis engine never started or could not read any frames, the results stop at the summary. Run it again if the engine failed; re-film if no body was found.
• No clear priority — the One Fix step only fills in when the analysis found a fix to recommend.

What to try: sign in and reopen the analysis. If it was withheld because of the clip, re-film using the fixes it lists — see why re-filming can come first.

• Different camera angle — rotation and path reads are not directly comparable.
• Different distance or height — you fill the frame differently, or the camera sat higher or lower, so posture and turn changes partly reflect the camera.
• Different frame rate — speed and timing changes are not directly comparable.
• One clip cropped your lower body, missed contact, or was not reliably analysable.
• A different shot or club — a chip against a full swing, for example.

What to try: re-film the retest to match the original — same angle, same distance and same equipment — from the same prop and spot. In RecordAssist, "Record the same angle again" reopens a setup you saved.

Even a clean comparison of two videos is a directional read, not a measured result. See retesting under the same conditions.

• The motion does not match the clip — each motion has its own phases and reads, so a chip analysed as a full swing, or a volley as a forehand, reads oddly.
• Handedness was wrong, or left on "Not sure".
• The camera angle chosen under Advanced capture settings does not match how the clip was filmed.
• The capture was graded Limited or Difficult, so the read is provisional.

What to try: choose the clip again with the corrected settings and re-run it. If everything was right, film another rep from the same spot — a finding that shows up again is more trustworthy than one that appears once.

Still think it is wrong? Disagreeing with your One Fix explains your options, and you can report a result that looks broken through the contact page.

To help us fix a problem quickly, include:

• the device and browser you used;
• the sport and motion;
• the exact message you saw, or the step where it stopped;
• whether it happens with more than one clip.

The form takes text only, and there is no need to send your video.

For privacy or deletion questions, the privacy policy explains what you can do yourself from Settings. Security issues go through the vulnerability disclosure policy.