Click the big button in the middle of the timeline that says “Create Frame Animation”. If your big button says something else, click the tiny arrow next to it and set it to “Create Frame Animation” before clicking.
Now it’s time to decide how long each frame will be displayed. A longer display time makes the GIF slower. Under each frame in the Timeline window, you’ll see the option to set the frame duration.
Play your GIF in Photoshop to get a feel for how the final product will look.
You can choose to make your GIF loop indefinitely. Select the loop options from the drop-down menu at the bottom of the Timeline window. You can choose for your GIF to play once, loop three times, or continuously loop forever.
To export your GIF, go to File > Export > Save for Web (Legacy). There are several options you can adjust to affect image quality. Pay close attention to dithering - you may want to experiment with its percentage until you get the results you want.
Congratulations! You’ve made your very own GIF—and you should be proud. Now it’s time to show off your work to the rest of the world.