Google built its reverse image search function into phones and tablets, albeit on a limited basis.
When you fire up images.google.com on mobile, the camera icon won't show up in the search bar. To get it, you'll need to load the desktop version on your mobile device. It works in Safari, but it performs best in the Chrome browser app (iOS(Opens in a new window) or Android(Opens in a new window)).
In Safari, tap the aA icon on the top left and select Request Desktop Site. In Chrome, tap the three-dot menu, scroll down on the menu that pops up, and select Request Desktop Site. On both browsers, that will load the desktop version of Google Images, and the camera icon will appear. Then you can upload photos from your camera roll.
Depending on your phone, Chrome also supports a reverse image search workaround. When you see the image in your browser that you want to search, hold your finger on it until a pop-up menu appears; pick Search Google for This Image at the bottom. Note: This will NOT work in the Google app or other browsers (not even in Safari). It only works in Chrome.
