How to open an animated GIF to edit in Paint by Zaweba
Animated GIF, WebP and APNG files open in Paint by Zaweba as Timeline frames, as plain layers, or as just the first frame. Here is when to pick each.

An animated GIF is really a stack of pictures with timing attached. To change one, you need to get at those pictures. Paint by Zaweba opens animated GIF, WebP and APNG files three ways: as Timeline frames with one layer each, as layers, or as the first frame only. You choose when the file opens, and the right answer depends on what you plan to do.
As Timeline frames
This is the choice when you want to keep the animation and change it. Each frame becomes a layer, and the Timeline shows them as frames you can play back. You can fix a typo in a caption across a few frames, recolour a logo that spins, crop the whole animation, add a frame, or change how long a pause lasts.
From there, View > Timeline gives you the playback controls and frame settings, and Export Animation writes the result back out as an animated GIF, WebP or a PNG sequence. GIF export uses Paint by Zaweba's own writer with palette, dither and frame differencing options, so you can keep an edited animation small.
As layers
Opening as layers gives you every frame stacked up as ordinary layers without the animation setup. That is useful when the animation is raw material rather than the end product. You might want to pick the best frame from a short burst, build a sprite sheet, or compare frames by toggling visibility. It is also a convenient way to make a static composite, such as an overlay of several frames to show a motion trail.
If you change your mind later, the Animation tools include Make Frames from Layers, so the layers can become a Timeline again.
First frame only
Sometimes you just want a still. A product shot saved as an animation, a thumbnail for a video, or a quick reference image all fall into this group. Opening only the first frame gives you an ordinary document without a stack of layers you would then have to delete. If the frame you want isn't the first, open as layers instead and delete the rest.
Practical tips
Animated GIFs are limited to 256 colours per frame, and many are heavily compressed. If you plan major edits, such as adding a gradient or a photographic element, expect the export to need careful palette settings. Animated WebP and APNG carry more colour, so edits from those sources usually survive with less fuss.
Watch for frames that rely on the previous one. Many GIF writers store only the parts of a frame that changed. Check a few frames on their own after opening, with the others hidden, so you know exactly what each layer holds before you start painting on it.
Keep the timings in mind too. If you add or delete frames, check the delays in the Timeline, because removing frames from a smooth loop can make it jump.
A doorway to the animation tools
Animated import is the front door to Paint by Zaweba's animation tools. Once frames are in, you have onion skins, tweening, keyframes and filter animations available, plus all the normal editing tools on each frame. That makes the app a practical place to tidy memes, fix banners, edit stickers and repurpose short loops, offline and without uploading anything to a web converter.