I'm developing a pinch zoom feature for a mobile app written in javascript and I want to test this in Google Chrome with the mobile device emulation feature. But I cannot find a way to test a pinch gesture.
I tried everything I could find on the internet (pressing Shift and moving the mouse, pressing Alt and moving the mouse), but none of this worked. Is there even a "native" way in Google Chrome to simulate a pinch zoom gesture?
btw I'm using the MacOs version of Google Chrome version 59.0.3071.86
Shift + mouse click & drag across the viewport
Works for me. Only problem is that the touchstart event will return 1 for originalEvent.touches
Pinch gestures have different listeners in different browsers but there is an outstanding lightweight library named hammer.js which handles pinch,swipe and .... pretty easy and fine in all browsers, Unfortunately it does not support Desktop Chrome, so you can not debug your web-mobile codes easily,
Shift-Mouse click&dragging on Desktop Chrome with hammer library also does not work fine, it activates hammer's Pan event instead of pinch and works just once!, after that it keeps calling Pan event when you move your mouse through your viewport which is quite annoying and makes the debug impossible.
Solution : The only convenient way, that I know, to test your gestures on a mobile browser is to use either Safari to Safari connection on ios/osx devices or Chrome to Chrome connection for android devices.
I use to debug my JavaScript codes with Chrome DevTools but in web-mobile projects I use Safari Web Inspector, because I have an iphone and a Mac!. you also can not debug your ios device with Desktop Chrome.
Take a look at this article to find out how to setup your Safari Web Inspector.
Note: you need to connect your iphone to your mac using usb-cable and enable Web Inspector on your iphone (Settings-> Safari -> Advanced -> Web Inspector) If you are unable to see Develop menu on your Safari, Go to Preferences and in Advanced tab check "Show develop menu in menu bar". the rest are explained in the above mentioned article.
Update
It is not possible to debug an ios device on a Windows Desktop Safari.
On Chrome 66, while in device simulation mode, double-click-drag up/down zooms out/in.
On Chrome v.71.x.x, you can pinch zoom pressing 'Toggle Device toolbar' at dev tools and after hold SHIFT and click-drag your mouse.
The last answer has five negative votes, but what I want to say is that the latest chrome browser(78) on Android platform does not have the function of zoom. You may have some problems with your understanding of viewport. The scale of viewport is pinchzoom. If you set it like this, your web page cannot trigger pinchzoom.
<meta name="viewport" content="initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
Your can set this way in your webpage
<meta name="viewport" content="initial-scale=1, maximum-scale=5, minimum-scale=1, user-scalable=yes">
The other answers have already said that shortcuts for pinch zoom.
With Mac OS you can use two fingers on the touch pad to simulate pinch zoom.
Maybe check the viewport setup in the meta tag:
<meta name="viewport" content="initial-scale=1">
Adding a maximum-scale to the viewport meta tag might influence the zoom:
<meta name="viewport" content="initial-scale=1, maximum-scale=1">
might be causing a problem for you.
You should also be able to zoom using the zoom percentage at the top of the developer tools page:
来源：https://stackoverflow.com/questions/44456764/how-to-simulate-pinch-zoom-in-google-chrome