Quick answer
What Screen DPI Estimate tells you
Explain browser pixel ratio and provide an estimate without claiming exact physical screen density.
- Observed here
- CSS pixel size, Device pixel ratio, Estimated physical pixels.
- How to interpret it
- Device pixel ratio is a scaling ratio, not physical dots per inch. Without a reliable physical screen measurement, browser dimensions cannot establish true panel DPI.
- Important limit
- Results reflect events and values exposed by this browser.
- Data handling
- Test values are calculated in this browser. Device Test Bench does not store a test result or create a device fingerprint.
Useful next comparison: Use the panel manufacturer physical size and native resolution when a physical pixel-density calculation is needed.
Understanding the result
What a result means
The estimate relates CSS pixels to devicePixelRatio and never claims exact physical DPI. True density requires reliable physical dimensions, which general browser pages do not receive.
Confirm the pattern by repeating css pixel size. Results reflect events and values exposed by this browser.
How to use this test
- Read the privacy and compatibility notes.
- Start the test and interact only inside the marked test area.
- Repeat the action several times and compare the live indicators.
- Use the troubleshooting section before deciding that hardware is faulty.
What this test checks
- CSS pixel size
- Device pixel ratio
- Estimated physical pixels
- Scaling explanation
What this test cannot check
Results reflect events and values exposed by this browser.
This test does not certify hardware or replace professional inspection.
Exact DPI requires reliable physical dimensions that browsers usually do not expose.
Common problems and troubleshooting
Record operating-system scaling and browser zoom before comparing devices. Use manufacturer specifications or a measured physical reference when exact print or calibration dimensions are required.
- Repeat the same observation. Focus the test surface and repeat “CSS pixel size” three times under the same conditions.
- Change one condition. Compare “Device pixel ratio” after changing only the relevant port, connection, browser setting or application.
- Rule out focus or interception. Close overlays and reserved shortcuts, keep the page visible and confirm that the live indicator changes during the action.
- Keep the result within its limit. Results reflect events and values exposed by this browser.
If the same pattern remains across relevant applications and connections, give the manufacturer or a qualified technician the repeatable observations instead of a guessed fault label.
Browser compatibility
devicePixelRatio is widely exposed but changes with zoom, scaling and monitor placement. Browsers may also apply privacy rounding, so the result is labelled as an estimate.
| Browser | Reference status | Evidence basis | Version | Notes | Checked |
|---|---|---|---|---|---|
| Chrome | Supported | Expected baseline | Not recorded | Feature detection is authoritative; permissions, platform and device support can change availability. | 2026-08-27 |
| Microsoft Edge | Supported | Expected baseline | Not recorded | Feature detection is authoritative; permissions, platform and device support can change availability. | 2026-08-27 |
| Firefox | Partial | Expected baseline | Not recorded | Feature detection is authoritative; permissions, platform and device support can change availability. | 2026-08-27 |
| Safari | Partial | Expected baseline | Not recorded | Feature detection is authoritative; permissions, platform and device support can change availability. | 2026-08-27 |
Privacy information
Test values are calculated in this browser. Device Test Bench does not store a test result or create a device fingerprint.
The public analytics allowlist does not accept pressed keys, typed text, pointer coordinates, media labels, device IDs, recordings, video frames or controller input. Test results are not written to LocalStorage.
Primary technical references
These specifications define the browser signals used by this test. They document web-platform behavior; they do not certify a particular device.
Frequently asked questions
Is this Screen DPI Estimate free?
Yes. The test works without an account, download or payment.
Is my test data uploaded?
Test values are calculated in this browser. Device Test Bench does not store a test result or create a device fingerprint.
Does this result prove my hardware is faulty?
No. It shows what the browser can observe. Repeat the test, compare another browser or device, and seek qualified support when the result matters.