It would be great to be able to use Cloudinary for responsive images.
For content images inside Markdown (or other formats), it could use presets and a Liquid syntax as in the Jekyll-Cloudinary plugin.
It would be even better if it could use native Markdown syntax and some "filters" in templates.
I already use Cloudinary, so I can help define the features, maybe even provide some code… ;-)
I, for one, (am completely biased but) think this is a great idea! And would of course love to help make it a reality.
I had some simmilar thoughts when seeing this: https://twitter.com/zachleat/status/943502658295476225 ...
@zachleat how exactly do you envision static asset handling things “layering on top?”
I think this is going to be closely tied to what gets formulated for #13.

This repository is now using lodash style issue management for enhancements (see https://twitter.com/samselikoff/status/991395669016436736)
This means enhancement issues will now be closed instead of leaving them open. The enhancement backlog can be found here: https://github.com/11ty/eleventy/issues?utf8=%E2%9C%93&q=label%3Aneeds-votes+sort%3Areactions-%2B1-desc+
Now that we have shortcodes - here's a (very basic) start: https://github.com/eeeps/eleventy-respimg
I've made huge progress towards my aim to use standard Markdown syntax for images and yet generate responsive images. I'm using Eleventy transforms for that, enhancing the standard images HTML <img src="…"> to <img src="…" srcset="…" sizes="…"> and even embedding it in a <figure> if/when it makes sense.
I'll try to release it soon as a plugin that would support Cloudinary at first (I'm using it), but potentially other image CDNs, or even home made solutions.
Sorry for the teasing, but I wanted to let you know it will come soon, at last. 😁
Teasing is over, here's my plugin for simple responsive images in Eleventy:
https://github.com/nhoizey/eleventy-plugin-images-responsiver/
eleventy-plugin-images-responsiver is "just" a thin layer between Eleventy plugin and transformations system and images-responsiver, a generic HTML transformation Node.js module for simple responsive images.
Eleventy uses Markdown-it to transform Markdown into HTML, and then runs the transform added by eleventy-plugin-images-responsiver, which calls images-responsiver to actually transform the HTML.
Neither eleventy-plugin-images-responsiver nor images-responsiver transform (resize) the image files, there are multiple ways to do so: https://nhoizey.github.io/images-responsiver/tutorial-05-images-urls.html
Most helpful comment
I've made huge progress towards my aim to use standard Markdown syntax for images and yet generate responsive images. I'm using Eleventy transforms for that, enhancing the standard images HTML
<img src="…">to<img src="…" srcset="…" sizes="…">and even embedding it in a<figure>if/when it makes sense.I'll try to release it soon as a plugin that would support Cloudinary at first (I'm using it), but potentially other image CDNs, or even home made solutions.
Sorry for the teasing, but I wanted to let you know it will come soon, at last. 😁