How to simulate touch gestures in browser, preferably chrome?

Open up the devtools and on the topleft corner there's an icon with a screen behind a phone. Click it to enable phone mode. You will know you are in phone mode because the page will be smaller and a circle will appear where your cursor was. Clicking will simulate a touch event.

If you go into Developer Tools (F12), enter responsive design mode (Ctrl + Shift + M) and select a touch-enabled device, you can change it so it triggers touch events when you interact with the page (rather than mouse events).

While on Chrome, press F12 to toggle Developer Mode.

Then, on the top-left of the developer partial, you will see a small icon saying "Toggle Device Mode" (Ctrl/CMD + Shift + M)

Then, you can switch between devices at the top.

This will mimic touch gestures made by a real device.

I would recommend Hammerjs's touch emulator. It gets you touch events like Chrome, but also multitouch events (pinch in particular). It's easy to install on your page while developing. I'm using it to test stuff written in Fulcro (React). Works perfectly.