You can see the mobile version of a website on your desktop in three ways. Each has its uses, and the right one depends on how close to a real phone you need to get.
Simlord runs in Chrome on a computer. Open this page there to add it.
Drag the edge of the window in. It's quick, but the site still knows it's a desktop, so you see a narrow desktop page, not the mobile site.
Open DevTools with F12, or Cmd+Option+I on a Mac, and press Ctrl+Shift+M, or Cmd+Shift+M on a Mac. Chrome sizes the page like a phone and sends a mobile user agent, inside the developer tools.
With Simlord, click the icon and pick a phone. The page fills the tab with the phone's frame, its browser bars and touch, and stays logged in.
DevTools' device toolbar is built in and free, and great for checking a breakpoint while you debug. It shows the viewport, not the phone. There are no browser bars, no current device frames, and DevTools itself takes half your screen.
Simlord shows the page the way a phone shows it, with Safari's or Chrome's toolbar taking its real room, the status bar and the notch or Dynamic Island. It keeps the device you chose while you browse, and you can take a screenshot or a recording of it.
Simlord opens and closes with Alt+Shift+M, and has shortcuts to rotate, to go to the next device, to take a screenshot and to record. You can change them in Chrome's extension shortcuts.
Something else? Write to support@simlord.eu.
In DevTools it's Ctrl+Shift+M on Windows and Linux and Cmd+Shift+M on a Mac, after opening DevTools. Simlord opens with Alt+Shift+M without DevTools.
Because the site checks the user agent or touch support, not only the width. A narrow window still reports a desktop browser.
Yes, any site you can open in Chrome, including ones you're logged in to.
The site gets a phone's size, identity and touch, so it responds as it would to a phone. Nothing changes for other tabs.
Free, no account needed. Works in Chrome, Edge and Brave.
Simlord runs in Chrome on a computer. Open this page there to add it.