Why two different resolutions are shown
Browsers report screen size in CSS pixels, a unit designed so that text stays a readable size on every device. Your panel's real pixel count is the CSS size multiplied by the device pixel ratio. A phone that reports 390 × 844 at a ratio of 3 has a physical 1170 × 2532 display — the number on the box.
The same applies on desktop. A 4K monitor running at 150% Windows scaling reports 2560 × 1440 CSS pixels with a ratio of 1.5, because the operating system is trading screen real estate for legibility. Neither number is wrong; they answer different questions.
| Value | What it answers |
|---|---|
| Screen resolution (CSS px) | How much layout space you have — what web designers target |
| Physical resolution | How many real pixels the panel has — what the spec sheet advertises |
| Device pixel ratio | How many real pixels are packed into one CSS pixel |
| Browser viewport | The visible page area, minus toolbars and scrollbars |
| Usable screen area | The screen minus the taskbar, dock or menu bar |
Common resolutions, named
- 1366 × 768 — the old budget-laptop standard. Cramped for modern work; avoid on a new machine.
- 1920 × 1080 (Full HD, 1080p) — still the most common laptop and monitor resolution, and the right default for most people.
- 2560 × 1440 (QHD, 1440p, “2K”) — the value sweet spot on a 27-inch monitor.
- 3840 × 2160 (UHD, 4K) — four times the pixels of 1080p. Needs scaling on anything under about 32 inches.
- 2880 × 1800 / 3024 × 1964 — typical high-density laptop panels, which report far smaller CSS sizes because their pixel ratio is 2 or more.
What the other readings tell you
Colour gamut reports whether your display covers standard sRGB or the wider Display P3 range. P3 matters for photo and video work and for HDR content; on an sRGB panel, P3 material looks slightly muted. Colour depth of 24-bit means 8 bits per channel, or about 16.7 million colours — standard.
CPU threads is the number of parallel threads your processor exposes, which is usually twice the physical core count on Intel and AMD chips with simultaneous multithreading. Device memory is deliberately rounded down by browsers to a coarse figure to limit fingerprinting, so treat it as a floor rather than an exact amount of RAM.
Max touch points is the quickest way to tell whether a device has a touch screen at all: zero means no digitiser. If it reports ten, confirm they all work with the touch screen test.
Verifying a device against its listing
This page is a fast, objective cross-check when a second-hand listing's specs look generous. Physical resolution either matches the model or it does not, touch points confirm a claimed touch screen, and CPU thread count is a useful sanity check against a claimed processor — a chip advertised as an 8-core that reports 4 threads is not the chip in the listing.
Two honest limits. Browsers withhold or round some values on purpose, so “Not reported” means your browser declined to answer rather than that the hardware is missing. And nothing here proves the model of a component — only its characteristics. Pair this with the dead pixel test and the refresh rate test for a complete picture of a display.
Comparing against new prices before you negotiate? Our best laptops for students in India guide lists current panel specs and prices, and casting a laptop to a TV explains what resolution actually reaches an external screen.
Frequently asked questions
What is my screen resolution?
It is shown at the top of this page, live. Use the physical resolution figure when comparing against a spec sheet or a marketing claim, and the CSS resolution when a designer or a support agent asks what resolution you are browsing at.
Why does my resolution look smaller than the one on the box?
Because of display scaling. Your operating system is enlarging everything so it stays readable on a high-density panel, and the browser reports the scaled size. Multiply by the device pixel ratio to get back to the panel's true pixel count.
Does the viewport size change when I resize the window?
Yes — every value here updates live. Resize the window or rotate your phone and watch the viewport and orientation rows change, while screen resolution and pixel ratio stay fixed to the hardware.
Is any of this information sent anywhere?
No. Everything is read by JavaScript in your browser and displayed on the page. Nothing is transmitted, logged or stored. The copy button puts the report on your clipboard so you can paste it into a support ticket if you choose to.