A responsive image polyfill for <picture>, srcset, sizes, and more
JavaScript HTML CSS
Latest commit d70b3e2 Mar 29, 2016 @jegtnes jegtnes Merge pull request #647 from thorsten/patch-1
Fixed version typo

README.md

Picturefill

A responsive image polyfill.

build-status Join Slack channel picturefill on npm

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 It is no longer maintained.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 3.0.2 is the current stable release.

Usage, Demos, Docs

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

The gotchas

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>

Contributing

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

Issues

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

Discussion

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

Support

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