Convert GIF to PNG

How to convert GIF to PNG

1. Choose one or more GIF images — drag them in or use the file picker.
2. Download the PNG — a single file, or a zip if you converted several at once.

The 256 colours were fixed when the GIF was made, and PNG cannot get the rest back

A GIF carries a colour table of at most 256 entries, and every pixel is an index into it. Whatever the image was before it became a GIF, the reduction to those values happened then, and the discarded colours were stored nowhere. Resolving each index to its palette colour and drawing the frame onto a canvas copies a reduced still faithfully — but an animated GIF is flattened to its first frame here, so the copy is only strictly lossless when the source held a single frame.

The visible signature of that reduction is dithering. A common error-diffusion default such as Floyd–Steinberg scatters pixels of two or three palette colours in a fine pattern, so the eye averages them into a colour the table never held. Those pixels are ordinary image data, not an effect applied when the GIF is shown, so the canvas copies them into the PNG exactly. A sky that stipples at 200 per cent zoom stipples identically once it is a PNG.

What the change of container alters is the ceiling on whatever happens next. A PNG is under no obligation to reference a table of 256 colours, so a gradient painted over the converted image, a recolour or a soft drop shadow is stored at full channel depth rather than pushed back through the old palette and dithered a second time. The inherited pixels stay exactly as the GIF fixed them; only the new ones escape the ration.

A converted PNG usually lands at or below the GIF — unless the GIF was heavily dithered

GIF compresses its indices with LZW; PNG runs each row through a filter and then DEFLATE. On flat GIF artwork — a few colours in long runs — the filters leave mostly repeated bytes and the result often matches or undercuts the GIF. That holds even though this canvas encoder writes full red, green and blue channels rather than the GIF’s compact 256-entry table, since the canvas offers no indexed-PNG output. A hand-optimised PNG would shrink it further; the canvas settles for a fast filter choice.

The exception is the dithered photograph. Error diffusion sprays the palette into a fine, near-random stipple, and that scatter is exactly what a row filter cannot predict — each pixel differs from its neighbours, so little compresses and DEFLATE has almost nothing to remove. A colour-rich, heavily dithered GIF can therefore leave the canvas as a truecolour PNG larger than the source it came from. The flatter and more poster-like the original, the more decisively the PNG comes out ahead.

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