A responsive image polyfill.

• Authors: See Authors.txt
• License: MIT

At the time, it helped us transition to responsive image HTML patterns until browsers supported them. Support and fallback strategies are now very good, and this project is no longer needed or recommended. Thanks everyone!`

Picturefill has three versions:

• Version 1 mimics the Picture element pattern with span elements. It is no longer maintained.
• Version 2 is a lightweight polyfill of the Picture element draft specification.
• Version 3.0.3 is the current stable release.

To find out how to use Picturefill, visit the project site.

Be it browser issues, the responsive images specifications, or Picturefill itself, there are a couple gotchas you should be aware of when working with Picturefill:

• Firefox 38 and 39 has some bugs [1] [2] [3] where images won't update on screen resize. These issues are addressed by Picturefill 3.0.0, and was fixed in Firefox 41.

• Per the picture spec, using % isn't allowed in the sizes attribute. Using % will fallback to 100vw.

• Trying to use the src attribute in a browser that doesn't support picture natively can result in a double download. To avoid this, don't use the src attribute on the img tag:

<picture>
    <source srcset="../img/sample.svg" media="(min-width: 768px)" />
    <img srcset="default.png" alt="Sample pic" />
</picture>

• If you only want to have an image show up at certain sizes, and not show up at others, you will need to use a transparent placeholder gif:

<picture>
    <source srcset="../img/sample.svg" media="(min-width: 768px)" />
    <img srcset="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=="
        alt="Sample pic" />
</picture>

For information on how to contribute code to Picturefill, check out CONTRIBUTING.md

If you find a bug in Picturefill, please add it to the issue tracker

Picturefill discussion takes place via Slack. For an invitation, visit https://pf-slackin.herokuapp.com/

There are currently no known unsupported browsers, provided that you use the markup patterns provided.