user32702: I have to create high quality GIFs with transparent backgrounds for a gig, Blender can render transparent videos with the quicktime codec, but do you know a tool to convert them to transparent GIFs, without quality loss? The only one I heard about is Photoshop, all online tools lower the resolution, and Virtualdub reduces the colors and doesn't convert to transparent GIF.

user4426: Export at ProRes 4444 "millions of colors+" with Alpha.
If you’re not on a Mac you can still use QuickTime based on these settings:
￼
More info here:
https://blender.stackexchange.com/questions/2050/any-video-formats-that-render-with-alpha-channel
Use something like GIF Brewery to make the conversion. GIF Brewery is free and available for Mac.
On a PC you could try https://www.screentogif.com/ or an online gif converter such as https://ezgif.com/optimize (if you don’t have access to Photoshop).
GIFs are an old format, and the quality for the file size is never great... Choices about resolution, file size and palette size can improve quality considerably. Examples based on Photoshop: https://blog.bannersnack.com/reduce-the-size-animated-gifs/

user26178: Based on your post, You have the wrong expectations, and for that, a wrong workflow. Let me explain.

Blender can render transparent "renders", they can be PNG sequences or can be compiled in a video that supports transparency. NOt every video file can support this.

"convert them to transparent GIFs, without quality loss?"


Quality is a process, it is not something that you "lose" somewhere. What you can potentially lose is information.
If you generate a flat colors animation on Blender when reducing the palette to the 256 allowed by gif format you would still have enough room because you actually planned the animation to have flat colors and just some of them.
But if you generated a photographic image or one with gradients, you did not plan them well enough considering the limitations of the GIF format. The Gif format is popular again because of the Flat design look.
If you have a gradient it needs to be adapted to a limited palette.
So, using GIF files as an output format requires a very controlled workflow.

The same with transparency. You can only have 1 of the 256 colors transparent. You can not have gradients.
If you need the gradients and smooth transparency you have some alternatives:
https://graphicdesign.stackexchange.com/questions/121859/creating-high-quality-animated-backgrounds-from-illustrator-files/121890#121890

And answering the question, you can assign a transparent color using Gimp.
Another option, if you like to write instructions: https://stackoverflow.com/questions/11389721/how-do-i-set-a-colour-to-be-transparent-in-a-gif-using-imagemagick
You can also look for some simple GIF makers, some can be free. https://www.google.com/search?client=firefox-b-d&q=Gif+maker%2C+Gif+creator

32702: <p>I have to create high quality GIFs with transparent backgrounds for a gig, Blender can render transparent videos with the quicktime codec, but do you know a tool to convert them to transparent GIFs, without quality loss? The only one I heard about is Photoshop, all online tools lower the resolution, and Virtualdub reduces the colors and doesn't convert to transparent GIF.</p>
 4426: <p>Export at ProRes 4444 &quot;millions of colors+&quot; with Alpha.</p>
<p>If you’re not on a Mac you can still use QuickTime based on these settings:</p>
<p>￼</p>
<p>More info here:</p>
<p><a href="https://blender.stackexchange.com/questions/2050/any-video-formats-that-render-with-alpha-channel">https://blender.stackexchange.com/questions/2050/any-video-formats-that-render-with-alpha-channel</a></p>
<p>Use something like <a href="https://gfycat.com/gifbrewery" rel="nofollow noreferrer">GIF Brewery</a> to make the conversion. GIF Brewery is free and available for Mac.</p>
<p>On a PC you could try <a href="https://www.screentogif.com/" rel="nofollow noreferrer">https://www.screentogif.com/</a> or an online gif converter such as <a href="https://ezgif.com/optimize" rel="nofollow noreferrer">https://ezgif.com/optimize</a> (if you don’t have access to Photoshop).</p>
<p>GIFs are an old format, and the quality for the file size is never great... Choices about resolution, file size and palette size can improve quality considerably. Examples based on Photoshop: <a href="https://blog.bannersnack.com/reduce-the-size-animated-gifs/" rel="nofollow noreferrer">https://blog.bannersnack.com/reduce-the-size-animated-gifs/</a></p>
 26178: <p>Based on your post, You have the wrong expectations, and for that, a wrong workflow. Let me explain.</p>
<ol>
<li><p>Blender can render transparent &quot;renders&quot;, they can be PNG sequences or can be compiled in a video that supports transparency. NOt every video file can support this.</p>
</li>
<li><p>&quot;convert them to transparent GIFs, without quality loss?&quot;</p>
</li>
</ol>
<p>Quality is a process, it is not something that you &quot;lose&quot; somewhere. What you can potentially lose is information.</p>
<p>If you generate a flat colors animation on Blender when reducing the palette to the 256 allowed by gif format you would still have enough room because you actually planned the animation to have flat colors and just some of them.</p>
<p>But if you generated a photographic image or one with gradients, you did not plan them well enough considering the limitations of the GIF format. The Gif format is popular again because of the Flat design look.</p>
<p>If you have a gradient it needs to be adapted to a limited palette.</p>
<p>So, using GIF files as an output format requires a very controlled workflow.</p>
<hr />
<p>The same with transparency. You can only have 1 of the 256 colors transparent. You can not have gradients.</p>
<p>If you need the gradients and smooth transparency you have some alternatives:</p>
<p><a href="https://graphicdesign.stackexchange.com/questions/121859/creating-high-quality-animated-backgrounds-from-illustrator-files/121890#121890">https://graphicdesign.stackexchange.com/questions/121859/creating-high-quality-animated-backgrounds-from-illustrator-files/121890#121890</a></p>
<hr />
<p>And answering the question, you can assign a transparent color using Gimp.</p>
<p>Another option, if you like to write instructions: <a href="https://stackoverflow.com/questions/11389721/how-do-i-set-a-colour-to-be-transparent-in-a-gif-using-imagemagick">https://stackoverflow.com/questions/11389721/how-do-i-set-a-colour-to-be-transparent-in-a-gif-using-imagemagick</a></p>
<p>You can also look for some simple GIF makers, some can be free. <a href="https://www.google.com/search?client=firefox-b-d&amp;q=Gif+maker%2C+Gif+creator" rel="nofollow noreferrer">https://www.google.com/search?client=firefox-b-d&amp;q=Gif+maker%2C+Gif+creator</a></p>
