Top-down replay
Your phone video, straightened into a flat track map with every car cut out and tracked frame by frame.
See what makes you faster.YOUR NEXT STEP
Opening your Sample 5 session…
MINI-Z LAP ANALYSIS FROM A PHONE VIDEO
See exactly where your lap time goes.
Film a session from above the track. ParaLLaps turns the video into a top-down replay with every car tracked, then shows your lap times, speed and grip, the corners where you lose time, and a ghost of your best lap to race.
The demo uses Sample 5: 59 seconds of three cars at RCHQ. Everything runs in your browser.
Find the time
Lap times, speed and grip for every lap, plus a heat map of where you lose time and how consistent your line is.
Race your ghost
Your best lap replays as a see-through car that restarts at the timing loop, so every lap is a race against it.
- Upload a videoShot from above the track, from a phone or a fixed camera.
- Mark the trackDrag four corners onto the track; the fisheye straightens itself.
- Keep your carEvery car is found automatically. Keep the ones you care about.
- Analyze and compareReplay, find the time, compare with your last session or the fast guys.
YOUR VIDEOS
Videos.
Upload a track video, mark the track once, and keep a session for every car you care about.
Red joins your points; thin blue extensions show where rails meet beyond the video frame.
Pan and pinch to zoom. Choose a corner, then tap to set it.
Play or scrub to choose a clear frame.
Mark the track corners
Drag the four handles onto the track's outer corners. On a rounded corner, put the handle where the two straight outer rails would meet. The fisheye fits itself once all four are placed.
No saved setup matches this video’s dimensions yet. Use Auto-detect corners.
Reuse only when the camera position, framing and lens mode match.
Corrects itself once all four corners are placed. Use − and + or the slider to fine-tune.
Top-down shape
Estimated during fitting. Measurement scale is confirmed in Step 2.
TOP-DOWN PREVIEW
Find a saved camera setup · optional
Use location and camera to find a transform saved in this browser. A fixed camera keeps its transform across layouts; each layout has its own grid and timing loop.
Select A, B, C and D at the outer grid corners.
More tools · tap exact corners, draw rail guides
For unusual camera angles: place each corner by tapping, and draw guide lines along rails to judge straightness.
Align the tile grid
The grid starts at your track corners, with the tile count read from the floor’s tile shades. Check it against the seams, then nudge. This grid becomes the replay crop.
Drag anywhere in the top-down view to move the grid. Fine-tune with the buttons below; one nudge is one top-down image pixel.
Place the timing loop
Match the timing loop to the real track loop. Place two endpoints across the lane; laps are timed when the car crosses this line.
Find cars & process
Every car on track in this time range is found automatically, including cars that leave the view and come back. Next you pick which cars’ runs to save.
Processing options
This exact file matches the preserved Sample 5 recording. You can reuse its verified analysis without rerunning tracking.
Set up turns
Turns belong to this layout: set them once and every recording of it uses them. Each turn runs from its entry through its apex to its exit; the gaps between turns are the straights.
- Drag a handle along the line to move it.
- Drag a turn label anywhere; its spot is saved.
- Add turn, then tap the line: entry and exit are proposed from how the line curves.
Extract and label
Location, layout & camera
Pick a found car and save its run. Save as many cars as you like; they share this recording.
No complete laps for this car. Move the timing loop across its path, or recheck laps from the saved tracking.
Save only part of this run
For two stints in one video, save each as its own session. Every complete lap inside the range is kept.
Check this car’s path and name before saving.
FIND YOUR NEXT COMPARISON
Session catalog.
Independent car runs, with their shared source recording retained.
YOUR SESSIONS
Sessions.
Every car run you kept from a video. Open one to replay it, find where the time goes, or race a ghost.
Sessions come from your videos: open a video, mark the track, then keep the cars you want. Classes, racer labels and notes are yours to organize them.
ROOF-MOUNTED 360 CAMERA
Sample 5 v2.5
59.1 seconds · 3 cars · 11 complete laps
LOCATION · LAYOUT · CAMERA
Sample 5 venue · Sample 5 layoutRoof 360 · Fixed cameraFITTED REPLAY · SOURCE CAR CUTOUTSScroll to zoom · Drag to pan
ORIGINAL CAMERA · SOURCE PIXELS
00:00.00000:59.100
FROM THE RECORDING
Laps worth a closer look
Analysis
Choose your laps.
FITTED ANALYSISScroll to zoom · Drag to pan
Where to focus next
Corners, ranked by time on the table
Each corner is timed from halfway along the straight before it to halfway along the straight after it, so the approach and the drive out count. Turns less than 1.5 m apart are one corner. Typical is your middle lap through it; fastest is your quickest. Line differences are measured toward the inside of each turn; differences smaller than the video can measure (5 cm, 0.2 m of turn-in, 0.5 km/h) are left out.
Reference lap speeds, corner by corner
TRACK SETUP
Make every tile count.
Match the seams, count the tiles, and place the timing loop.
Finish track setup to open this session.
Confirm the grid, track bounds and timing loop once. Saved recordings reuse their confirmed setup.
SETUP FOR THIS RECORDING
Saved camera / layout setupsNo saved setup yet
The preview is saved only when you confirm the track. Personal cameras need a position check for each recording.
MATCHED GRID · FULL CAMERA VIEWScroll to zoom
The grid is editable. Check seams in several parts of the track.Full image retained
WIDTH——
HEIGHT——
TILE SIZE50 × 50 cmSuggested bounds
TWO LAPS. ONE TRACK.
See where the time goes.
Start together, or line up at any section. Each lap keeps its real pace.
Choose two laps to compare.
Select a car in Review, then choose any two of its laps—or compare it with another car.
AObserved
Complete lap—
Lap elapsed—
Speed · km/h est.—
Turn G est.—
BObserved
Complete lap—
Lap elapsed—
Speed · km/h est.—
Turn G est.—
Keep replaying the rest of the straight and the next corner after the lap ends. Uses available following footage; synthetic laps use an estimated continuation. Official lap times stay unchanged.
SHARED TRACK · INDEPENDENT SOURCE CLOCKSB is ghosted · both cars visibleScroll to zoom · Drag to pan
0.000 s
Offset +0.000 s
Lap A stays still while you move B.
AT THE SAME COURSE POSITION
Time gained and lost
—B’s arrival time minus A’s arrival time.Whole-lap difference —
Tap the chart to inspect a section. Dashed sections use inferred correspondence.
CORNER BY CORNER