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Measure card centering in millimetres — with your phone
What it does: point your phone at a card. The app finds the card's edges and the printed frame, corrects for tilt and lens distortion, and reports left/right and top/bottom centering in millimetres — then checks it against PSA, BGS, CGC, SGC, TAG, ACE and ARS at once. Front and back, in about ten seconds.
Free, no sign-up, works in the browser on iPhone and Android. Photos are processed on your device and never uploaded.
PSA 10 allows 55/45 on the front. On a card with a 2.5 mm border that is a 0.25 mm offset from centre — about three hairs. A 0.5 mm ruler cannot read it, and drawing lines on a photo by hand drifts by 0.3 mm or more with tilt. Centering Cam detects all four edges automatically; in a 40-photo test with known ground truth, 95% of measurements were within ±0.11 mm.
What makes it different
Live overlay. Register a reference card (a PSA 10 scan, the official image, or your own best copy) and the app projects it onto the camera view, aligned to the artwork. You see the centering offset before you press the shutter.
Cards without a frame. Full-art, borderless and card backs have no printed frame to measure from. The app measures the print offset against a reference template instead, so they are measurable at all.
Shared templates. Backs are identical within a game, so one shared back template serves everyone. Templates are shared as numbers, never images, and are graded for reliability before they are offered.
Honest about uncertainty. Shadows, glare, blur and tilt are detected. If the number sits on the 55/45 line, the app holds the verdict and asks for a reshoot instead of guessing.
Seven graders, one shot. Front and back limits for PSA, BGS, CGC, SGC, TAG, ACE and ARS are checked together, so you know where a 10 is realistic before you pay a fee.
How to measure
Open the app, pick the card size (63×88 mm for Pokémon, One Piece, MTG; 59×86 mm for Yu-Gi-Oh!).
Put the card flat on a plain dark cloth (white paper for dark or black-bordered cards) and hold the phone straight above it.
The outline turns green and the app shoots automatically. Read the ratio, the mm margins and the grader verdicts.
Flip the card and shoot the back; the app combines both sides into one verdict and keeps a record with corner close-ups.
Yes. The web app is free with no account. A premium tier removes the daily measurement limit.
Does it upload my photos?
No. Detection runs in your browser with OpenCV compiled to WebAssembly. Only optional shared templates are sent, and those are numbers, not images.
How accurate is it?
In a 40-photo test with known offsets (including tilt, blur, glare, black and white backgrounds), 95% of measurements were within ±0.11 mm, about ±2 points of ratio on a 2.5 mm border.
Which cards does it support?
Any rectangular card: Pokémon, One Piece, Magic: The Gathering, Yu-Gi-Oh!, Dragon Ball Fusion World, Duel Masters, sports cards. Custom sizes can be entered in mm.
Can it measure full-art or borderless cards?
Yes, with a reference template: register the official image or a graded copy and the app measures the print offset against it, overlaying the reference live on the camera view.