Camera
Fix Guide
Face Shape Detector Not Working? Here’s How to Diagnose It
The face shape detector usually works on the first try — but camera permission errors, unexpected results, and inconsistent readings across sessions are common enough that a dedicated troubleshooting reference is useful. This guide covers everything that can go wrong and exactly how to fix it.
Issues fall into two categories: the camera won’t load at all (access problems), or the camera loads but the result doesn’t look right (quality problems). The sections below cover both — plus a re-testing methodology for cases where you’re not sure if the result is accurate. This page assumes you already know how to use the camera and focuses entirely on diagnosing problems after the fact.
Why the Same Person Gets Different Results
If you’ve used the detector more than once and got different face shape results, you’re not alone. The AI measures geometric ratios from pixel data — which means any change in lighting, camera angle, hair position, or head position changes what it measures. Your face shape hasn’t changed; the input data has.
Here are the five variables that cause inconsistent results most often, and the specific measurement each one affects:
Camera above eye level compresses the forehead and makes the face look wider relative to its length — often causing oval to read as round. Camera below eye level does the opposite. Even 10–15cm above eye level is enough to shift the classification.
Shadows on one side of the face affect where the jaw and cheekbone landmarks are detected. Different lighting between sessions — morning window vs. evening lamp — changes which zones are shadowed and shifts those specific measurements.
If your hair is pulled back more thoroughly in one session than another, the forehead width and jaw edge measurements will differ. Even a few strands over the hairline affect the forehead reading.
A slight tilt introduces asymmetry into every width measurement — the model reads a different jaw width on the raised side versus the lowered side. A 5-degree tilt is enough to shift the classification in borderline cases.
A smile raises the cheeks and shifts the jaw contour. If you smiled in one session and had a neutral expression in another, the soft-tissue measurements will differ — sometimes enough to affect the shape category.
How to interpret inconsistent results
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Troubleshooting Camera Issues
Camera issues fall into two categories: access problems (the camera doesn't load at all) and quality problems (the camera loads but the result is unexpected). Each has a distinct diagnostic path.
Access Problems
Permission denied — camera blocked
The browser has remembered a previous denial. In Chrome: click the padlock icon in the address bar → Site settings → Camera → Allow. In Firefox: click the padlock → Connection secure → More information → Permissions → Use the Camera → Allow. In Safari: Settings → Websites → Camera → find the site → Allow. After changing the permission, reload the page.
No camera detected — permission dialog never appeared
This usually means another application has exclusive access to the camera. Close video call apps (Zoom, Teams, Meet), streaming software (OBS), and any other browser tabs with camera access. On Windows, check Task Manager for processes with camera activity. On Mac, check the camera indicator light — if it's on with no visible application, force quit from Activity Monitor. Restart the browser after closing other apps.
Camera loads but shows a black screen
Common on laptops with privacy shutters — check if the physical camera cover is slid open. On some devices, a driver issue prevents the browser from receiving the video stream; restarting the browser or the device typically resolves it. If the issue persists across browsers, the camera driver may need updating via Device Manager (Windows) or System Report (Mac).
Camera permission granted but preview shows wrong camera
Devices with both front and rear cameras may default to the rear camera. Look for a "flip camera" or "switch camera" button in the interface — on mobile, this toggles between cameras. For face shape detection, always use the front-facing camera. On desktop, if you have multiple camera devices, the browser's camera selection can be changed in the browser settings.
Camera works on another site but not here
The site may be blocked specifically. Check browser settings for site-level camera permissions and ensure this site is set to Allow rather than Ask or Block. Also check if a browser extension (ad blocker, privacy extension) is blocking the camera API — disable extensions temporarily to test.
Quality Problems — Unexpected Results
If the camera worked but your face shape result seems wrong, use this diagnostic sequence before retaking:
Was there a shadow on one side of your face?
If yes, one side's jaw or temple landmarks were likely estimated rather than measured. Move to better lighting and retake.
Was your head tilted, even slightly?
Tilt is the most common cause of unexpected oval-to-round or round-to-square misclassification. Look at the captured frame — if your head is even slightly off-vertical, retake with extra attention to keeping your head straight.
Did your hair cover any part of the forehead, temples, or jawline?
Hair over the hairline or jaw causes the model to underestimate the width of those zones. Re-clip the hair more thoroughly and retake.
Were you wearing glasses?
Glass frames interfere with brow and eye-area landmarks. Remove them and retake.
Were you smiling or had a tense expression?
Muscle movement shifts soft tissue. Relax the jaw fully and retake with a neutral expression.
Was the face too small in the alignment guide?
Move closer to the camera so your face fills most of the guide area, and retake.
If the Result Is Consistent Across Multiple Good Photos
How to Do a Reliable Re-Test
If your first result was unexpected and you want to get a definitive answer, follow this controlled re-test protocol — it eliminates the variables that cause inconsistency and gives you a result you can trust.
Choose a consistent location
Pick a spot you can return to: ideally a chair facing a window where you control the lighting. Using the same spot for all retests eliminates lighting variation as a variable. Note the time of day — morning and afternoon window light differ significantly as the sun angle changes.
Standardize your preparation
Hair in the same position for every test — ideally pulled fully back into a bun or clip. No glasses. The same neutral expression. These are the variables that most commonly change between casual retests without the user noticing.
Set the camera to exactly eye level
Prop the device on a fixed surface at eye level — a phone stand, a stack of books, or propped against a monitor. Do not hold the phone yourself, because arm angle varies between captures. The camera-at-eye-level requirement is the single most important technical condition.
Take 3 captures, not just 1
Take three photos in quick succession without moving, then choose the one where the face looks most centered and evenly lit. Don't take one photo, submit it, then retake if you don't like the result — that introduces selection bias toward the result you prefer. Choose based on photo quality, not result.
Run two full sessions on different days
Your face changes slightly with hydration, sleep, and time of day. Two sessions on separate days, both under the same controlled conditions, give you a comparison that accounts for natural daily variation. If both sessions agree, the result is reliable.
“If two carefully done sessions agree, trust the result — even if it doesn’t match your expectation. The AI measures geometry, not self-perception.”
Borderline Results: When You’re Between Two Shapes
If controlled retests consistently alternate between two face shapes — say, oval and oblong, or square and rectangle — you are genuinely borderline between those categories. This is a normal, valid result. Most face shapes exist on a spectrum rather than falling cleanly into one category.
The practical solution: read the styling advice for both categories and apply the recommendations that overlap between them. The overlap is your most reliable guidance — it works for your face regardless of which side of the boundary you’re on.
Frequently Asked Questions
Does the camera feature work on all browsers?
Is my video stream recorded or stored?
My result was oval last time but round this time. Which is right?
Can I use a photo from my camera roll instead of taking a new one?
What resolution does the camera need to be for good results?
Does the camera use flash?
Further Reading
Naeem Ullah
Founder, Face Shape Detector • AI & Facial Proportion Researcher
Founder of faceshapedetector.app · 4+ years in facial proportion research · 200,000+ monthly readers
Naeem Ullah is the founder of Face Shape Detector and has spent over four years researching how facial landmark geometry translates into practical styling decisions. His work draws on training principles from professional hairstyling, optician certification programs, and academic literature on facial symmetry and proportion. He built the face detection system at the core of this tool and personally writes and reviews every styling guide published on this site. His guides are read by over 200,000 users monthly across 140+ countries.