GIF only supports one fully transparent color per frame, with nothing in between, so any anti-aliased edge around a transparent shape was already baked into the file as solid, opaque pixels. WebP's alpha channel can hold smooth partial transparency, but converting a GIF frame won't add that smoothness retroactively, since the source pixels never had it to begin with.
A jagged edge or color fringe isn't something conversion can fix
If a converted logo or icon shows a hard, slightly jagged edge or a thin colored halo around the transparent boundary, that came from the original GIF, not from the WebP conversion. Fixing it means going back to a source file with real anti-aliased transparency, usually a PNG or a vector original, rather than adjusting anything in this tool.
This tool always encodes lossy, there's no automatic lossless mode
The WebP format itself supports both lossy and lossless compression, but this tool always uses WebP's lossy mode, controlled entirely by the quality slider from 60 to 95. It does not detect what kind of frame you're converting and switch to lossless for it. For icons, screenshots or flat graphics where exact pixel fidelity matters more than file size, pushing the slider toward 95 gets visually close to lossless, but it isn't pixel-perfect the way GIF to PNG's lossless output is. If a converted graphic needs to match its source exactly, byte for byte in every pixel, GIF to PNG is the tool that actually guarantees that, not a high quality setting here.
WebP has been safe to rely on for a while now
Older guides sometimes warn about WebP support gaps in older Safari versions, but that's no longer a real concern in 2026. Every major browser renders WebP natively, which makes it a reasonable default for a converted GIF still without needing to keep a JPEG or PNG fallback around for most everyday projects.