Screen Resolution Checker

Your screen resolution is shown at the top of the tool card above — for example, 1920 × 1080. This is the size of your screen in CSS pixels, the logical unit browsers use for layout. Below it you will also find the estimated physical resolution, which accounts for display scaling. If the two numbers differ, your display is running with scaling enabled — which is normal and recommended on high-resolution panels. The card updates live by design: resizing the browser window changes the viewport, zooming changes the physical estimate, and moving the window to another monitor re-measures that display.

Modern high-resolution displays use scaling to keep text and icons at a comfortable size. A 4K monitor at 150% scaling reports 2560 × 1440 CSS pixels even though the panel physically renders 3840 × 2160. The browser’s screen.width and screen.height always use CSS pixels, so the reported resolution is the scaled — logical — resolution. Multiply it by the device pixel ratio and you get the physical resolution, which is exactly what the physical resolution estimate on this page does for you.

Screen resolution describes your entire display — the full monitor or phone screen. The viewport is the visible portion of a web page inside your browser window: it excludes browser toolbars, interface bars, sidebars, and scroll bars. On a maximized browser the viewport is slightly smaller than the screen; on a small floating window it can be much smaller. Web developers use viewport size (not screen resolution) to build responsive layouts, which is why both values are shown side by side on this page. The available screen area shown alongside is the display minus permanent system furniture: on a 1920 × 1080 Windows screen the default taskbar leaves roughly 1040 pixels of height for maximized applications.

Open this page and read the physical resolution estimate — with browser zoom at 100% it matches the panel’s native resolution, because scaling cannot change how many pixels the hardware renders. You can cross-check in your operating system: on Windows, go to Settings › System › Display and look at Display resolution (the recommended entry is the native one); on macOS, open System Settings › Displays — the "Default for display" option typically uses the native resolution with scaling for sharpness. This also lets you verify a monitor before buying it: move the browser window onto that display and the card re-measures it — a genuine 21:9 ultrawide reports 3440 × 1440 or 2560 × 1080, not a marketing name.

Yes — completely. There is no charge, no sign-up, no download, and no limit on how often you can check. Every measurement happens locally in your browser: the page reads your screen, window, and display settings, and renders them on screen. No screen data, device fingerprint, or usage statistic is sent to any server, and nothing is saved after you close the tab. You can even run it offline once the page has loaded.

Yes, and often substantially. Pushing more pixels means the graphics processor does more work every frame, so a game running comfortably at 1920 × 1080 may struggle at 3840 × 2160 on the same hardware. On the desktop the effect is much smaller because static content is redrawn only when it changes. If a game stutters after you raised the resolution, lowering it — or enabling an upscaling mode — is usually the fastest fix.

Mobile devices typically report a logical resolution in CSS pixels rather than the panel native resolution, because the operating system scales the interface so that touch targets stay a comfortable physical size. A phone with a 1080 × 2400 panel may report roughly 393 × 851 CSS pixels. The physical resolution estimate on this page combines the reported size with the device pixel ratio to approximate the true panel, which is the number worth quoting in a specification.

On Windows, open Settings, then System, then Display, and set Scale back to the value marked as recommended; the recommended resolution is normally the native one as well. On macOS, open System Settings, then Displays, and choose Default for display, which selects the native resolution with scaling applied for sharpness. After either change, reload this page — the reported values update immediately and should match the expected panel specification.

Completely. Everything you see is read from your browser’s own interfaces — navigator, screen, Intl, and feature detection — and rendered locally. No data is transmitted to a server, no fingerprint is computed, and nothing is stored after you close the tab. That stands in contrast to many "what is my browser" sites that log user agents or run analytics on the results. You can verify the behavior yourself: load the page, disconnect from the internet, and it still works.

Browsers deliberately round or cap details that could identify you. Device memory (navigator.deviceMemory) is reported as a rough bucket — 0.25, 0.5, 1, 2, 4, or 8 GB — and never exceeds 8, even on a 32 GB machine. CPU core counts reflect logical processors as the browser sees them, which can differ from physical cores. Operating system versions come from reduced user agents or Client Hints and may be coarse. These approximations are privacy features, not bugs.

Client Hints are a newer, structured alternative to the long user agent string. Instead of one opaque line, the browser exposes a set of labelled fields such as brand list, full version, platform version, architecture, and bitness, and it may withhold the high-entropy values unless a site asks for them. This page reads whatever your browser chooses to expose, which is why Chromium browsers here show more precise detail than Firefox or Safari.

No. This page reads only the same information any website can obtain from standard browser APIs — user agent, screen size, supported features — and combines nothing into a unique identifier. There are no cookies, no canvas fingerprinting, no font enumeration, and no analytics. The page works identically offline, which is the simplest proof that nothing is sent anywhere.