Cloud Four Blog

Technical notes, War stories and anecdotes

Don’t use <picture> (most of the time)

Browser support for the picture specification is landing and as Marcos Cáceres said, it is time to “go forth and <picture> all the things!

Except you shouldn’t. You shouldn’t <picture> all the things.

But you should start using picture now for responsive images. No reason to wait.

Confused? You’re not alone.

<picture> vs. picture

Standards are developed in non-linear fashion. Ideas evolve and merge. And often at the end of a lengthy process, you look back and wonder how you got here.

And in this case, where we ended up is with a specification called ‘picture’ that contains much more than the <picture> element. The picture specification includes srcset and sizes and you can use those attributes without using the <picture> element.

Knowing which use case you’re solving tells you what solution you need

One of the earliest pieces of work that the Responsive Images Community Group undertook was defining the use cases for responsive images.

You don’t need to know all of the use cases, but you do need to know the difference between the two most common use cases in order to know which part of the picture specification will solve your problems. The two common use cases are:

  • Resolution switching — In the resolution switching use case, we need to select a different source of the same image because we need a different resolution for any number of reasons. These reasons include the image being used at a different size based on the size of the screen, the pixel density of the screen, or to avoid downloading unnecessarily large images.1

  • Art direction — In the art direction use case, there is some reason why we need to modify the content of an image under certain conditions. Maybe we need to crop the image differently on small screens. Or perhaps we’re working with a hero image that contains text and simply providing a smaller version of the image won’t work because the text will be unreadable.

Basically, if you could resize an image without making any other changes, and have a new source that solves your responsive images needs, then you’re talking about the resolution switching use case. If you need to change anything other than resolution, you’re talking about art direction.2

For most responsive images, you won’t need the <picture> element

Unless you’re solving for art direction, you don’t need to use the <picture> element. In fact, you’re likely doing your users a disservice by using the <picture> element.

The picture specification supports syntax that can be used without the <picture> element. An example syntax, borrow from Yoav Weiss’ excellent article Native Responsive Images, might look like this:

<img src="cat_500px.jpg"
    srcset="cat_750px.jpg 1.5x, cat_1000px.jpg 2x"
    width="500px" alt="lolcat">

Which will provide the browser with different options for display density. Or in a more complex example:

<img sizes="(max-width: 30em) 100vw,
            (max-width: 50em) 50vw,
            calc(33vw - 100px)"
    srcset="swing-200.jpg 200w,
            swing-400.jpg 400w,
            swing-800.jpg 800w,
            swing-1600.jpg 1600w"
    src="swing-400.jpg" alt="Kettlebell Swing">

There is a lot to digest in those examples, and unfortunately, I don’t have the space to cover the syntax here. Instead, I recommend reading Yoav’s article or one of the additional resources listed below if you want to understand the details.3

When you use the srcset and sizes attributes on an <img> element, you are providing information that the browser can use to make an informed decision about what image is appropriate for the user based on a bunch of factors that you are unaware of.

As a web designer or developer, you have no way of knowing how much bandwidth the user currently has or if they’ve declared some sort of preference for the density of images they want. If we provide browsers with information via srcset and sizes then browsers can make smarter decisions about the appropriate image source.

In fact, I hope that browser makers compete on how they handle srcset and sizes by developing new user settings or smarter algorithms to help them pick the right images to download.

But none of that is possible when you use the <picture> element and its media attributes:

<picture>
    <source media="(min-width: 45em)" srcset="large.jpg">
    <source media="(min-width: 32em)" srcset="med.jpg">
    <img src="small.jpg" alt="The president giving an award.">
</picture>

When you specify the media queries for sources, you are providing rules to the browser that it must follow. The browser has no discretion to make smart decisions about what to download based on user preference, network, etc.

You should use the power to dictate what image gets downloaded sparingly. In fact, you should only use it when you’re solving for art direction, not for resolution switching.

For the majority of the images on the web, <picture> is the wrong solution

Last year, Yoav tried to figure out what percentage of responsive images fell under the art direction use case. The answer: 25%.

Responsive design is still early so we may find that the percentage changes, but it is unlikely that we’ll ever reach a point where the number of art directed responsive images out-numbers the number of resolution switching ones.

Therefore, for most responsive images, the <picture> element is the wrong solution. You should be using <img> with srcset and sizes.

The future of the web depends on us getting this right

Getting this right matters a great deal to the future of the web. We’ve seen in the past what happens when web developers create a large installed base of suboptimal web pages. We end up with browsers adopting other browser’s css prefixes or media types such as mobile and TV ignored by all mobile phones and TVs.

If we create thousands of web pages that use the <picture> element for resolution switching, we doom ourselves to having to specify every single image needed instead of letting the computers—the browsers—do what they do best and automatically find the right image based on a multitude of variables.

Worse, we doom our users to a future where they are unable to take advantage of whatever browser advances come because we’ve taken the browser’s discretion away and dictated what image should be downloaded.

Perhaps we need to stop referring to the picture specification

A lot of this confusion comes from the fact that we have a specification that ended up with picture in the title even though the specification covers more than just picture.

For those who have been heavily involved in the development of a solution for responsive images, picture is a nice shorthand. That’s why you see that even it referred to as <picture> in Chrome Status and Modern IE Status.

Using picture as a shorthand it creates confusion when talking to people who are just now looking to implement responsive images. I asked the Responsive Images Community how they’ve been handling this confusion.

Bruce Lawson says:

I tend to refer to “picture and friends” or, generically, “responsive images”

And Odin Hørthe Omdal adds:

I always talk about responsive images, and I think I probably say the respimg specification.

So I’m going to attempt to do the same. I’m going to break myself of the habit of referring to the picture specification and instead refer to responsive images specification even if that isn’t technically the name of the specification. I think people will understand what I mean, and it will help ensure more people understand that it isn’t all about <picture>.

Simple guidelines for using the responsive images specification

To summarize:

  • The picture specification contains more than just the <picture> element. Think of it as the responsive images specification.
  • For most responsive images, you shouldn’t use the <picture> element. You should use srcset and/or sizes.
  • The way to know when to use the <picture> element is based on the use case you’re trying to solve.
  • If you’re solving for the art direction use case, use the <picture> element. Anything else, you should stick to srcset and sizes.
  • Getting this right early—before we have thousands of pages using <picture> incorrectly—is critical for the future of the web.

And with that, I will amend what Marcos wrote to say, “Go forth and make all your images responsive!”


  1. In the responsive images use case document, resolution switching is described with three different examples: Resolution-based selection, Viewport-based selection and Device-pixel-ratio-based selection.
    And yes, they are all different reasons why you want to select a different resolution source, but they all involve resolution switching which is why I’m lumping them together.
  2. You may find this article I wrote on A Framework for Discussing Responsive Images to be a good high-level overview of the use cases.

  3. Some additional articles to help you understand the full features of the picture specification: HTML5 Rocks: Built-in Browser Support for Responsive Images, Srcset and sizes and Responsive Images Done Right: A Guide To <picture> And srcset by Eric Portis.

Updating responsive image guidelines in preparation for AEA Austin

Last year, I wrote 8 Guidelines and 1 Rule for Responsive Images based on some consulting work we had done for a client with over 800,000 images on their site.

In preparation for An Event Apart Austin, I decided to revisit the guidelines and see if they still applied in light of browsers implementing the picture specification.

In particular, I was curious how much caution we should take when implementing solutions for responsive images. Last year, I wrote:

The one and only rule for responsive images: Plan for the fact that whatever you implement will be deprecated

Is that rule dated with the browsers standardizing on the picture specification?

I asked for some feedback from the responsive images community group on the risk of the specification changing and how much we should be hedging out bets.

Simon Pieters, who works for Opera, wrote:

It is also normal that the first shipping implementations are not perfectly compliant with the spec. For instance they might have implemented a slightly out of date algorithm and missed that something was changed, or simply have bugs. Then it is fixed in a future version and that might break your code if you only tested in one implementation.

This is no different from any other feature that is shipped on the Web. To avoid issues, test in multiple implementations and validate.

Should we still be hedging our bets a little?

No, that’s not necessary.

Now, a couple of people on the list responded that they have a large set of images on the sites they manage and centralizing image handling and markup still made sense. So perhaps it isn’t a rule, but still an idea that you should consider based on the scope of the site and the number of images involved.

I’ll leave the final word on the matter to Marcos Cáceres who played a critical role on the picture specification and works for Firefox, reassured me with these words:

Once it gets into the wild and people start using it, it can’t change. Thems is the golden rule of the Web.

Spec is stable and the browsers are coming this month – go forth and <picture> all the things! Make the web beautiful again :)

As Marcos says, go forth and <picture> all the things!

P.S. If you’re interested in more on this topic, join us at AEA Austin or AEA Orlando. You can use discount code ‘AEAGRIG’ to get $100 off your registration. I hope to see you there!

Did you try to reach us?

I’m embarrassed to admit it. I screwed up and if you tried to contact us over the last few months, there is a chance your message didn’t get through.

Specifically, messages sent via the contact form on our site weren’t always reaching us.

In case this saves anyone else from making the same mistake, here’s what happened. We switched our mail to Google. Instead of having an email alias, we had to use a Google Group.

Everything seemed fine for a few months, but then at some point Google Groups decided contact form submissions were spam. And we didn’t have any moderators for the group.

I set up the Google Group so I must have screwed it up. Because things worked great for several months, we don’t know when the problem started and how many messages were missed.

The most painful part about screwing up something like this is that there is no way to know who you need to apologize to.

So if you tried to contact us and didn’t hear back, I’m very sorry. The contact form is fixed now. We’d love to hear from you.

Slow and ugly

Many years ago at a previous job, I was responsible for pushing our organization to adopt a new ticket tracking system. We decided to use an open source project called Request Tracker (RT).

This was before the days of Zen Desk and similar services. RT matched our requirements best. I worked with our sysadmins and engineers to get the software running and rolled it out to the organization.

It was a failure. People were openly swearing at RT, and I’m sure they were privately cursing me for forcing them to use it.

While I sympathized with the complaints, I felt hamstrung because RT was deployed on an underpowered server and we had not been allowed to modify the look and feel. Back then RT was a bit of a dog both from a performance and aesthetics perspective.

As I worked with engineering to secure better hardware and get someone to assist with the design, the number of grievances continued to pile up.

One conversation stands out to me. A member of the management team told me that the fact that customers couldn’t reset their password in RT was unacceptable and as long as that was true, we couldn’t use RT.

I listened to the objections and kept a list of the issues that were raised, but I kept my focus on making RT faster and more attractive.

A few months later we relaunched RT. It was met with skepticism, but to the credit of my colleagues, they gave me and it a second chance.

It wasn’t too long after the relaunch that previous skeptics were swearing by the system. One of the team members became the master of RT and made a bunch of process improvements that I would have never considered.

What happened to that list of complaints that I gathered? We didn’t address a single one of them. Passwords worked exactly as they did before.

We simply made RT fast and attractive.

I have a simple rule when it comes to user experience: when something is slow and ugly, nothing else matters.

Until you address those two issues, you’re not going to be tell whether other complaints are real or red herrings.

An Event Apart 2014

Speaking at An Event Apart is intimidating. Last year, I was privileged to speak twice, and I was terrified each time.

While I thought I gave a good talk both times, I realized after my first talk that I had misjudged the audience. I feared I had whiffed on my only chance to speak and wouldn’t be invited back.

So you can imagine my surprise and delight when Eric and Jeffrey asked me back this year. I swore that this year I would nail it.

What I learned last year was that people come to AEA expecting not only to be wowed by fantastic speakers, but also to take home a tangible things that they can implement.

So I put together a presentation called Mobile First Responsive Design. We know that over 90% of responsive designs are built poorly. This talk teaches you how to build in a responsible manner.

I presented the talk for the first time at AEA Atlanta. It is always difficult to judge your own talks, but based on the feedback from attendees, I think it worked. At minimum, I know people went home with a long list of things that they could do immediately.

I’m giving this presentation two more times. Once next month at AEA San Diego and in October at AEA Orlando.

I’m really proud of the way the talk has come together. I’d love it if you could join me at one of the two AEAs that I’m going to be speaking at.

But even if you can’t make it to San Diego or Orlando, An Event Apart puts on one of the best conferences in our industry. You should attend. And if you do, use ‘AEAGRIG’ on checkout to receive $100 off the price.

That discount code applies for all of the 2014 events—even the ones I’m not speaking at.

I hope to see you in San Diego or Orlando!