Very cool site, I especially loved the write-up, bravo!

Nice, bookmarked.

But if you're serious about reducing carbon waste, don't make visitors download 7.5MB to load the webpage.

Great work

Have you seen vert.sh? It does on-device conversion of audio, images, and documents and is open source too.

Does not appear to be open-source, but was built from at least 90% open-source software.

And if you happen to have wasm or web workers disabled, you get an unhelpful "Processing 0/0 files…" message that just hangs forever.

There is also https://squoosh.app/.

I was unsatisfied with the discussion of transparency. You mention to "jump to png", but I just scrolled to the heading and it tells me why jpg is better, in some cases, than png, not how to satisfy turning a png with transparency into a competent jpeg analog.

Of course, if you meant "use the png format" instead of "look at the header", that's likewise unhelpful.

Not sure if there's actually a suggestion in here. I entered the site thinking "if you want a jpg, this is the app". Any question I had about other formats was moot because this is the app for jpgs. But then you discussed the other formats so it seemed like you had some workarounds or ways to use jpgs in place of the other formats, and that left me unsatisfied whereas your saying nothing probably wouldn't have? Again, not sure if there's anything actionable in there, just letting you know my experience with the site.

Note: please don't turn your screenshots and digital art into JPG. JPG uses compression based on natural lighting. It works well for photos, but it's the wrong solution where run-length encoding will do much better (e.g. in screenshots). Black text (or cartoon art) on white backround always looks lousy when converted to JPG.

How a user of such a web-site may be sure that it really deosn't upload photos somewhere, even it claims not to do so?

Be careful, you may run into surprises with the XYB stuff in jpegli. Most should support it, since it uses an ICC color profile, but if the decoder does not handle it I'm not entirely sure what happens. I ran into a handful of strange issues a few years ago when testing this out, though it was all relatively old software.

Can't wait for them to come out with composite file types.

Where I could make one HTTP request and get a json blob and the associated image at the same time.

Then separate them on the client side and add them to the Dom.

Maybe this is just some niche use-case, but I tested it with a 268x98 png screenshot, and it made the image bigger and worse: https://files.catbox.moe/7so3z6.png