Quick answer
What this guide helps you determine
Separate sensor specifications, requested constraints, delivered stream dimensions and displayed CSS size.
Begin with the observable browser result, repeat it under the same conditions, and change one connection, setting or application at a time. A browser result narrows likely causes but does not certify hardware or decide a repair.
Scope of this check
Webcam resolution involves at least four different sizes: sensor specification, requested constraints, delivered stream dimensions and on-page display size. Only the delivered videoWidth and videoHeight describe the frames currently reaching the browser.
Step-by-step method
- Start the camera and record the active stream dimensions and aspect ratio. If the tool offers a selector, repeat with the intended camera because a built-in and USB device can expose different modes.
- Request another supported size and wait for the stream to stabilize. A request is a preference or constraint, not proof that the sensor captures that exact mode without cropping, scaling or binning.
- Compare the same camera in a conferencing application. That app may choose a lower size for bandwidth or performance. Treat manufacturer specifications as hardware limits and the browser result as the current session mode.
What to check first
Use these checkpoints to keep the comparison focused. Record the visible behavior rather than assigning a fault label too early.
- Read videoWidth and videoHeight
- Do not infer the sensor maximum
- Check aspect ratio as well as pixel count
How to read what you see
| Observation | What it can suggest | Useful next check |
|---|---|---|
| videoWidth and videoHeight match the requested mode | The browser delivered that frame size for this stream. | Use it as session evidence, not a sensor certification. |
| The preview looks large but dimensions are small | CSS enlarged a lower-resolution stream. | Judge the reported stream dimensions rather than page size. |
| Another app uses a lower resolution | Its bandwidth, processing or call policy differs. | Review the app’s video quality settings and network conditions. |
Common mistakes to avoid
- Do not advertise a sensor maximum based only on browser output.
- Do not compare resolution while two apps compete for the camera.
- Do not ignore aspect-ratio crop when comparing sizes.
Build evidence another person can use
Write down the exact action, visible result and whether it repeats. Include the browser family, operating-system family, connection type and the single comparison that changed the result. Quote the observation directly—for example, “videoWidth and videoHeight match the requested mode”—then add where it occurred and which comparison changed it.
Change one condition per comparison and return settings that have no effect. Follow model-specific manufacturer instructions before firmware changes, cleaning, disassembly or warranty action.
When to seek qualified support
If the same problem remains in multiple applications and on another compatible connection or computer, collect the repeatable observations and contact the manufacturer or a qualified technician. Stop using equipment that is physically damaged, unusually hot, wet, sparking or unsafe. Device Test Bench cannot inspect electrical condition or make a repair decision.
Privacy during testing
Our public tests process key events, pointer values, media streams and controller input locally. Do not send private recordings, complete typed text or device identifiers when asking for help. A short description of the behavior, browser and page URL is normally enough.
Questions readers ask
Does 1920×1080 prove a true 1080p sensor?
No. It proves that a 1920×1080 stream was delivered; internal scaling and the physical sensor are not exposed.
Why does resolution drop during a call?
The conferencing service may adapt to bandwidth, CPU load, layout or account settings.
Primary technical references
The following specifications define the browser APIs discussed in this guide. They are primary web-platform references, not product repair manuals.