On a desktop computer, reverse Google image search from your phone is a breeze.
Google has, to a lesser extent, integrated. Google has, to a lesser extent, integrated a reverse image search feature into phones and tablets.
The camera icon does not appear in the search bar when you start a Google image search on an Android or iPhone. You must load the desktop version onto your mobile device while in the Chrome browser app for iOS and Android to see it. Scroll down and select Request Desktop Site from the three-dot menu. This will launch the desktop version and display the camera icon, allowing you to import photos from your camera roll. Chrome may also support a reverse image search workaround depending on your phone. Hold your finger on the image you want to search for until a pop-up menu appears; select "Google for this image" below. Please keep in mind that this will NOT work in the Google app or other browsers.
Microsoft's Bing, the other major search engine, also performs reverse image searches, but calls them "visual searches." A video camera-like icon appears in the search box at the top of www.bing.com/images. When you click, you are prompted for an image URL, which you can use to load an image or drag and drop into an image.
On mobile, the same settings apply; simply click the Bing camera icon in any mobile browser. A pop-up window appears, requesting that you grant Bing access to your camera; accept or decline with a tap.
Tap the Browse button in the bottom left corner of the next screen.