Selecting a sex loads the relevant reference dataset for angle grading.
Step 2 -- Upload videos (all three required)
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Side view
Film from directly beside the runner
Best: Someone moving alongside you at the same pace. Good: Someone panning the camera to follow you. OK: Stationary camera, you run past it. Wear clothes that contrast with the background.
REQUIRED
◉
Front view
Film from directly in front
Run straight toward the camera. Do not run at an angle -- even a slight angle will skew hip drop and knee alignment measurements. Wear contrasting clothes against the background.
REQUIRED
●
Back view
Film from directly behind
Run straight away from the camera. Keep the camera dead center behind you, not at an angle. Wear contrasting clothes against the background.
REQUIRED
Recording tips for the best results
⏱Keep clips short: 3 to 8 seconds. We only sample 20-40 frames from each video, so longer clips just add unnecessary footage. A few seconds of steady running is ideal.
📷Stay close to the camera. The runner should fill most of the frame. If you are too far away, the pose model cannot accurately identify joint positions.
⚠Nothing should block your body. Treadmill handrails, other runners, or objects in front of you will hide joints and reduce detection accuracy. If filming on a treadmill, position the camera so the display and handrails are not covering your arms or legs.
🏃Consider filming both outdoors and on a treadmill. Treadmill running can change your form -- your stride length, foot strike, and trunk lean may differ from outdoor running. If you want a complete picture, analyze one of each and compare the results.
🎨Use a uniform background that contrasts with your clothing. The pose model works by identifying your body against the background. If your clothes blend into the background (e.g., dark clothes on a dark track, or grey clothes against concrete), detection will suffer. A turf field, a plain wall, or any backdrop that is a clearly different color from what you are wearing will give much better results.
☀Avoid very bright or very dark lighting. Overexposed (washed out) or underexposed (too dark) video makes it harder for the model to distinguish your body from the background. Even, natural lighting works best. Avoid filming directly into the sun or in deep shadow.
All video processing happens locally in your browser. Nothing is uploaded or stored anywhere.
MP4 / MOV / WebM -- Fully private -- No data uploaded
Scanning stride phases
Analyzing your videos for key moments of the running gait cycle.
Preparing...
Preparing...
Before you finish: review every card below
We made a first pass at detecting each phase of your running gait. Now you need to open each card, check the frame, and make sure detection is strong. This is what makes your results accurate.
1
Click on every card below
Each card represents a specific moment in your stride. Click on each one to open it. You will see a skeleton overlay on your video and a detection quality reading.
2
Get every card to "Strong detection"
The large detection quality indicator at the top of each card should read "Strong detection" in green. If it does not, click the Analyze button again, or use the scrubber to pick a clearer frame.
3
Make sure each frame matches its description
Each card describes what the frame should look like (for example, "the moment the left foot contacts the ground"). If the auto-selected frame does not match, use the scrubber to find the right moment and click Analyze again.
4
Then click "Complete analysis"
Once every card shows Strong detection and the correct frame, scroll to the bottom and click Complete analysis to generate your full report with coaching recommendations.
ⓘ
Why does this matter? The accuracy of your final report depends entirely on the quality of these frames. A frame with weak detection or the wrong moment selected will produce inaccurate angles and unreliable coaching cues. Taking a minute to check each card is the difference between useful feedback and noise.
If you are consistently getting weak detection across multiple cards, the issue is usually the video itself -- the runner may be too far from the camera, partially blocked by equipment, the clip may have too much motion blur, or the clothing may blend into the background. Wearing clothes that contrast with the background (e.g., a bright shirt on a green turf field) and filming in even lighting will make the biggest difference. Re-recording a short, close, well-lit clip with good contrast will help more than adjusting frames.
Left side
Right side
Trunk lean
▸ Within range
▴ Above range
▾ Below range
All phases analyzed -- ready to complete
Review the report below to finalize your analysis
Your running form report
Based on your video analysis, here is what we found. Detected issues include an explanation of what it means, why it might matter, what could be causing it, and specific cues to work on. Click any detected issue to expand the full breakdown.
Understanding your stride
Every runner's stride is highly individual, shaped by body proportions, joint mobility, sporting history, injury history, age, and many other factors. What is optimal for one person may be quite different for another — whether that is stride length, knee angle at toe-off, or any of the dozens of metrics that can be analyzed. There is no single "perfect" number for any of these.
That said, there are general principles that can be optimized within what is natural for your gait to help you become a more efficient, more resilient athlete. An efficient running stride typically has these things in common:
Low ground contact time — less time on the ground each step means less load and more time traveling forward in the air.
A cadence that fits your body — not too low (heavy, plodding steps) and not too high (spinning without covering ground). Most runners do well somewhere in the 170-185 range, but taller runners may naturally be lower.
Stride length that matches your speed naturally — longer is not always better. Stride length should come from push-off power and flight time, not from reaching forward.
Appropriate vertical oscillation — some up-and-down movement is necessary, but you want a good ratio of stride length to vertical bounce (often called "vertical ratio").
A slight forward lean from the ankles — not from the waist — to work with gravity rather than against it.
Compact, efficient arm carriage — driving from the elbows to help produce vertical lift and optimal knee drive each stride, not swinging wide or low.
Tracking your progress with wearable data
If you have a running watch or wearable that measures stride length, ground contact time, and vertical oscillation, you can use those numbers to track how form cues are working in real time. For example, if reducing your elbow angle and driving from the elbows produces a more efficient stride, you would expect to see a longer stride length, higher vertical oscillation, a similar vertical ratio, and reduced ground contact time.
Why small changes add up
When a form change reduces ground contact time and shifts cadence closer to your optimal range, the cumulative effect can be surprisingly large. Consider these examples:
EXAMPLE A: HIGH CADENCE RUNNER
Cadence drops from 190 to 185 spm Ground contact time drops from 230 ms to 225 ms
EXAMPLE B: LOW CADENCE RUNNER
Cadence rises from 165 to 170 spm Ground contact time drops from 250 ms to 230 ms
Both of these scenarios result in over 2 minutes less ground contact time per hour of running. That is 2 fewer minutes of load going through your muscles and tendons — and 2 more minutes spent in the air, traveling forward efficiently. The energy savings and injury risk reduction from that kind of shift are meaningful, and they come from changes that most runners would barely notice in the moment.
Save this analysis
Give this session a name so you can find it later and compare it to future sessions.
Side view measurements
A note about these reference ranges: The bell curves and ranges below are based on data from elite-level marathoners. Very few recreational runners will match these ranges across every metric, and that is completely normal. A value outside the elite range does not mean something is wrong or needs to be changed. Running mechanics are highly individual, and what matters most is efficiency and comfort within your own body. This data is provided for informational context only -- not as a target to chase or a diagnosis of a problem.
All angles below are measured in degrees and compared to reference ranges from elite runners. Only the angles that are biomechanically relevant for each gait phase are shown -- a dash indicates the metric is not applicable for that phase. Click any column header to open and re-examine that phase.
▸ Within range -- value falls inside elite reference band
▴ Above range -- value is above elite reference band
▾ Below range -- value is below elite reference band
-- Not analyzed
1
Phase
⚠ Not auto-detected
⚠ Not automatically detected
Use the scrubber to find the best matching frame, then click ↻ Analyze.
Frame adjustment
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frame
jump to:
Overlay key Left side Right side Trunk lean Center
What to look for
Estimated angles for this frame compared to elite reference ranges. The bell curve shows where your value falls relative to the reference population. Accuracy depends on video quality, camera angle, and keypoint confidence.