Facebook tries Google's WebP image format; users squawk

This shows the same image in JPEG and WebP, with WebP on the right. At this resolution, you're unlikely to see any differences.
This shows the same image in JPEG and WebP, with WebP on the right. At this resolution, you're unlikely to see any differences. (Click to enlarge.) Stephen Shankland/CNET

Facebook has begun using a Google image format called WebP that could lower its network costs and speed up its Web site. But the move has angered some members.

When people upload JPEG photos, the social-networking juggernaut converts them into the WebP format . And now it also apparently has begun delivering those images to people with browsers that can handle them, which today means Chrome and Opera.

Even if it's just a limited test, Facebook's scale and influence means that's a major endorsement of Google's image format.

But problems arise when it's time for people to do something with those images beside gaze upon them in the browser. Google has positioned WebP as an image format for the Web, at least to start, but when people save them to their hard drives, edit them, or reshare them, problems arise. Windows, OS X, Photoshop, and most other software can't handle WebP.

One Facebook user complained on the WebP mailing list:

As of yesterday, I've been able to download funny pictures from Facebook from friends in correct formats, but now they are downloading as an additional extension of .webp??? How do I fix this? It states that I'm downloading a .jpg, but it keeps coming up with "Save file as .webp" I've tried scrolling down and click on all files to save it as, but then the picture will not show up. Help????

One option is to use Internet Explorer, Safari, or Firefox, which at least today don't support WebP. And Opera users who don't want WebP can set their browser to pose as IE when visiting Facebook. But such measures can be inconvenient and not obvious to ordinary computer users.

"How do I disable this monster?" one Chrome user asked. "I do graphic design and I find it beyond annoying to have to have a special viewer for this thing, I want my images to be in .jpg. like it was before."

Speed, at a price?
The developments show the perils of improving the foundations of something as vast as the Web: introducing new technologies can improve performance or features in one area but break what was working in another. Even if only a small fraction of Web users notice, that can be a very large number in absolute terms.

The good news is that the more people experience a problem with an important technology, the faster it's likely the problems will get fixed -- in this case through software support elsewhere.

CNET contacted Facebook for comment and will update this post with their reply.

WebP, part of Google's effort to make the Web faster, offers smaller file sizes than JPEG, meaning that pages can load faster and that not as much data must be transferred over the network. WebP also is flexible: it offers animation and transparency support, and can replace PNG images as well in situations where lossless compression is desirable.

Thus far, only Chrome and Opera support it, but Mozilla is re-evaluating its earlier opposition to WebP for Firefox in light of some major non-Google Web sites showing support. Google also has improved the format to address some of Mozilla's earlier concerns.

Trying out WebP on Facebook
It appears that not everyone gets WebP images by default on Facebook right now. But curious people can scrutinize the images with a compatible browser.

To do so, find an image's page on Facebook -- I've uploaded a small gallery of assorted shots. Right-clicking on an image in most browsers gives you an option to open the image in a new tab, which in a browser that doesn't support WebP will show the JPEG version of the image. Then select the address, copy it into the address bar of a WebP-compatible browser such as Chrome, add ".webp" to the end of the filename, and you should see the WebP version.

In my testing, I found only subtle differences between the original JPEGs I uploaded and the WebP versions Facebook created from them.

For example, in one shot of a stained-glass window, (221KB JPEG, 136KB WebP), the purple patches behind Eve are a bit brighter with JPEG, and the skin on Adam and Eve has less detail with WebP.

In this comparison of some sunflowers (159KB JPEG, 103KB WebP), the WebP version shows increases color saturation from the JPEG original.

And in this shot of a boy playing in the waves (82KB JPEG, 59KB WebP), the WebP version seems to me to lose some detail in the water and with the aireborne droplets.

These are just a few tests, though, so don't read too much into them. WebP will change significantly with different encoding parameters, for example. Most of the shots were from a digital SLR with much higher image quality and more pixels than what a mobile phone produces. And these WebP images were converted from JPEGs; results might differ if they were created from the original raw photos, as were the JPEGs themselves.

WebP supporters and new tests
One WebP fan is Everything.me, creator of a mobile app for Firefox OS or Android that presents people with a dynamically generated array of Web apps. Co-founder and Chief Technology Officer Joey Simhon said WebP is good for both PNG files with transparent regions and with JPEG.

"WebP files have proven to look (to the naked eye) as good as JPEG's and weigh less," Simhon told CNET.

WebP logo

Another fan of WebP is CDN Connect, a content delivery network company that hopes to get ahead by easing Web developers' image-support pains. Founder Adam Bradley said he'd like to see a particular browser change: a change to information called the HTTP accept header that the browser sends to a server. With the change, browsers could tell servers they can handle WebP, and servers could start delivering those images immediately without workarounds.

Happily for Bradley, Google is trying out accept header support.

The decision isn't being made lightly. Adam Barth, a Chrome development leader at Google, has been hesitant to modify the accept header. "It's 100x easier to add a byte to every HTTP request than it is to remove a byte. Every byte you add is small, but the cruft accumulates over time and bloats the platform," he said in a comment. Other problems: the extra bytes in the accept header get sent from the browser to the server, a direction where network capacity is typically more constrained, and the vast majority of times at least for now the data is useless unless Web servers are updated to use it.

But fans of the approach can rejoice, because Google added WebP accept-header support to Chrome. Except when people are using the very raw Canary edition of Chrome, the feature will be disabled by default.

"Now, interested folks should be able to test it out," said Google WebP developer Urvang Joshi.