Responsive Images, Part 10: Conclusion

Written by Jason Grigsby on

Phew. We made it! We’ve come to the end of the Responsive Images 101 series.

Before we part ways with this series, I want to pass along some tips, resources and final thoughts on where responsive images are heading next.

Responsive image audits

Were this a book, I would have devoted a chapter to responsive image audits. It is the first thing we do when we start looking at how to convert a site to responsive images.

And it is most likely your next step towards taking what you’ve learned and applying it to your sites.

Fortunately, I wrote about these audits in great detail recently. Instead of repeating it in the 101 series, I encourage you to read what I wrote about responsive image audits now. Consider that article Part 9a.


Browser support for responsive images standards is growing rapidly. As of August 2015, Chrome, Opera and Firefox all support picture, srcset, sizes, and type.

Microsoft Edge and Safari support srcset with display density (x) descriptors, but not the width descriptors. Microsoft has started development to support the full responsive images standard.

Apple hasn’t committed to supporting the standard yet, but Apple knows responsive images support is important and Yoav Weiss has been contributing to the WebKit implementation.

When it comes to image-set(), there is still a lot more work to be done.


But even if all the browsers currently supported the responsive images standards, we’d still need a way to help older browsers understand the new syntax. That’s where the PictureFill polyfill comes in.

PictureFill will allow you to use the new responsive images syntax now.

Automating your image processing

In Part 9, I said that humans shouldn’t be picking image breakpoints. Instead, we should have software doing this automatically for us.

I want to expand on this point and say that most of what we deal with when it comes to responsive images is not something that designers and developers should be thinking about on a regular basis.

The goal for most organizations should be to centralize image resizing and processing and automate as much of their responsive images as possible.

In my ideal world, a responsive images workflow for resolution switching would look something like this:

  • Where possible, use resolution independent SVG images.
  • When creating or modifying the design of templates, the template author provides the sizes attribute for the various images in the template.
  • The srcset attribute with width descriptors is inserted by the server which does all of the heavy lifting of figuring out what image breakpoints to choose for each image.
  • Content authors never worry about any of this. Their only responsibility is to upload the highest quality source available and let the image resizing service take care of the rest.

This isn’t a far-fetched scenario. Many organizations already have image resizing services. And if your organization doesn’t, I maintain a spreadsheet of image resizing services and tools that you can consider (be sure to read the explanatory blog post as well).

And many content management systems are starting to look for ways to incorporate responsive images. The Responsive Images Community Group (RICG) maintains a WordPress plugin and they are currently looking at how to add it to WordPress core. Drupal 8 will ship with a responsive images module (more details).

The only thing these image resizing services need to add is support for figuring out how many image sources to supply for a given image and to output the proper markup for those image sources. They may not even need to worry about the markup if Client Hints takes off.

(More on Client Hints soon. This is a 201 topic.)

But regardless of how you automate it, I believe that centralizing image resizing and processing is essential to maintaining your sanity. When we talk to new companies exploring responsive images, one of the first things we assess is their image workflow and how much of it we can automate.

Future of responsive images

We’re just getting started when it comes to responsive images. We have thousands of sites to update to use the new image standards. Many organizations need to update how they handle images to centralize and automate what has until now been a manual process.

Even though there’s still a lot of work ahead of us, it feels like we’re finally on the downhill slope. We’re no longer struggling to find solutions that everyone can agree on. Implementations are landing in browsers. We have PictureFill to help us fill the gaps.

And now the wider web development community is beginning to look at how they are going to implement these new standards which means that we can start learning from each other.

If you’ve read this entire 101 series, you have everything you need to get started with responsive images. I can’t wait to see what you do with the new standards. Please share what you learn!

Thank you for reading.

Responsive Images 101 Series

  1. Definitions
  2. Img Required
  3. Srcset Display Density
  4. Srcset Width Descriptors
  5. Sizes
  6. Picture Element
  7. Type
  8. CSS Responsive Images
  9. Image breakpoints
  10. Currently Viewing:Conclusion
Jason Grigsby

Jason Grigsby is one of the co-founders of Cloud Four, Mobile Portland and Responsive Field Day. He spends far too much time obsessing over mobile and the web. Follow him at @grigs.


Fab series Jason, thanks.

I ran some tests to look at the network requests to confirm what the browser downloads, and the results were troubling. Chrome got it "wrong" nearly a third of the time, with the most common problem that it requested multiple sizes of the same image, completely negating the expected gains from responsive images.

You can see a write up at

Nigel Anderson


UPDATE: It is a confirmed bug in Chrome "that probably affects Android too". According to caniuse, support for srcset with sizes is only 63% anyway, but with Chrome implementation suspect, it means only Firefox and Opera can be counted on, i.e. 10% support at best. We are still some ways off this being ready for production unfortunately.

Excellent, excellent work! A "must read" tutorial series. Will it become an eBook for purchase somewhere?

Great articles but gutted you left ImageProcessor off your list. :( I'm working really hard to ensure that anyone working with .NET can manage their images for the web for free. Docs are at and the Github repo can be found at

Thanks Jason for the series. Using graphicsmagick to crop image to different resolutions.

Excellent series, Jason! Thank you!

I was recently introduced to task runners like Grunt. I'm curious about your thoughts on using them, in conjunction with image processors like Imagamagick, as substitutes for the forthcoming services that will support the ideal responsive workflow you laid out. Is that the best we can do if we're a one-person show?

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