Viewport Meta Tag Simulator - Online Test Mobile Rendering
Change the viewport meta tag and see how a page would render at different device widths. Understand responsive basics.
UD5 Toolkit
Change the viewport meta tag and see how a page would render at different device widths. Understand responsive basics.
See outerWidth, innerWidth, outerHeight, innerHeight, screenX/Y, and availWidth/Height live. Understand the viewport.
See your website inside iframes at multiple breakpoints simultaneously. Side‑by‑side responsive testing.
Enter a URL and view it in three iframes: mobile, tablet, and desktop side‑by‑side. Quick responsive check.
See the current viewport width/height, document size, scrollbar width, and pixel ratio. Essential responsive data.
Build a proper <meta name='viewport'> tag with width, initial‑scale, and user‑scalable options. Avoid common mobile rendering issues.
See exact dimensions of your current browser inner/outer window, screen resolution, and pixel ratio. Developer debug.
Detect your current screen resolution, viewport dimensions, and device pixel ratio. Useful for responsive design testing. No data collection.
Convert pixel values to viewport‑relative units (vw, vh, vmin, vmax) based on a selected breakpoint. Precise responsive design.
Enter a URL and drag a slider to change the viewport width smoothly. See exactly where your layout breaks. No iframe limits.
Preview any website inside emulated device viewports (iPhone, iPad, various resolutions). No screenshot, live interaction in an iframe. Local tool.