GIF is fundamentally limited to a palette of 256 colors per frame, a constraint baked into the format since its creation in 1987. JPEG and most modern image formats support millions of colors, so this gap matters more than it might seem. When a GIF is created from a photograph or any image with smooth color gradients, the encoder has to approximate those gradients using only the 256 colors available, which it typically does through dithering, a technique that mixes adjacent pixels of different colors to create the visual impression of a color that isn't actually in the palette. Up close, dithering looks like a fine speckled or noisy texture rather than a smooth gradient.
This is the reason some GIFs convert to JPEG looking slightly rough or grainy even at high JPEG quality settings. The roughness isn't something the JPEG encoder introduced. It was already present in the GIF's color data because of the 256-color limit, and the JPEG conversion simply preserves whatever was there rather than fixing it. This is most visible in GIFs with smooth gradients, like sky backgrounds or skin tones in a photograph, and almost invisible in GIFs with flat, simple colors like cartoons, logos, or screen recordings, since those rarely need more than 256 colors to begin with.
Why the first frame specifically, and what to do if it's the wrong one
This tool always extracts the first frame of an animated GIF rather than trying to guess at a more representative or visually interesting frame. The reason is technical consistency: the first frame is unambiguous and predictable across every GIF, while picking a different frame automatically would require some judgment about which frame best represents the animation, a decision that varies wildly depending on the content and can't be made reliably without seeing the result. Many GIFs, especially ones built from short video clips or memes, happen to use their first frame as a title card, transition frame, or blank moment before the main content begins, which means the extracted JPEG can sometimes be visually unrepresentative of what the GIF is actually about.
If the first frame isn't the one you want, the practical workaround is to trim the GIF down so your desired frame becomes the new first frame, or to take a screenshot of the specific moment you want while the GIF is playing and use that screenshot as your source image instead. For static GIFs, meaning ones with no animation at all, this distinction doesn't apply since there's only one frame to extract. If you're converting a GIF that needs to keep its transparent background rather than getting a white or black fill, the GIF to PNG converter extracts the same first frame but preserves alpha transparency in the output.