Chromium Blog
News and developments from the open source browser project
WebP, a new image format for the Web
giovedì 30 settembre 2010
As part of Google’s initiative to make the web faster, over the past few months we have released a number of tools to help site owners speed up their websites. We launched the
Page Speed
Firefox extension to evaluate the performance of web pages and to get suggestions on how to improve them, we introduced the
Speed Tracer
Chrome extension to help identify and fix performance problems in web applications, and we released a set of
closure tools
to help build rich web applications with fully optimized JavaScript code. While these tools have been incredibly successful in helping developers optimize their sites, as we’ve evaluated our progress, we continue to notice a single component of web pages is consistently responsible for the majority of the latency on pages across the web: images.
Most of the common image formats on the web today were established over a decade ago and are based on technology from around that time. Some engineers at Google decided to figure out if there was a way to further compress lossy images like JPEG to make them load faster, while still preserving quality and resolution. As part of this effort, we are releasing a developer preview of a new image format,
WebP
, that promises to significantly reduce the byte size of photos on the web, allowing web sites to load faster than before.
Images and photos make up about 65% of the bytes transmitted per web page today. They can significantly slow down a user’s web experience, especially on bandwidth-constrained networks such as a mobile network. Images on the web consist primarily of lossy formats such as JPEG, and to a lesser extent lossless formats such as PNG and GIF. Our team focused on improving compression of the lossy images, which constitute the larger percentage of images on the web today.
To improve on the compression that JPEG provides, we used an image compressor based on the VP8 codec that Google
open-sourced
in May 2010. We applied the techniques from VP8 video intra frame coding to push the envelope in still image coding. We also adapted a very lightweight container based on
RIFF
. While this container format contributes a minimal overhead of only 20 bytes per image, it is extensible to allow authors to save meta-data they would like to store.
While the benefits of a VP8 based image format were clear in theory, we needed to test them in the real world. In order to gauge the effectiveness of our efforts, we randomly picked about 1,000,000 images from the web (mostly JPEGs and some PNGs and GIFs) and re-encoded them to WebP without perceptibly compromising visual quality. This resulted in an average 39% reduction in file size. We expect that developers will achieve in practice even better file size reduction with WebP when starting from an uncompressed image.
To help you assess WebP’s performance with other formats, we have shared a selection of open-source and classic images along with file sizes so you can visually compare them on
this site
. We are also releasing a conversion tool that you can use to convert images to the WebP format. We’re looking forward to working with the browser and web developer community on the WebP spec and on adding native support for WebP. While WebP images can’t be viewed until browsers support the format, we are developing a patch for WebKit to provide native support for WebP in an upcoming release of Google Chrome. We plan to add support for a transparency
layer
, also known as
alpha
channel in a future update.
We’re excited to hear feedback from the developer community on our
discussion group
, so download the
conversion tool
, try it out on your favorite set of images, and let us know what you think.
Posted by Richard Rabbat, Product Manager
Etichette
$200K
1
10th birthday
4
abusive ads
1
abusive notifications
2
accessibility
3
ad blockers
1
ad blocking
2
advanced capabilities
1
android
2
anti abuse
1
anti-deception
1
background periodic sync
1
badging
1
benchmarks
1
beta
83
better ads standards
1
billing
1
birthday
4
blink
2
browser
2
browser interoperability
1
bundles
1
capabilities
6
capable web
1
cds
1
cds18
2
cds2018
1
chrome
35
chrome 81
1
chrome 83
2
chrome 84
2
chrome ads
1
chrome apps
5
Chrome dev
1
chrome dev summit
1
chrome dev summit 2018
1
chrome dev summit 2019
1
chrome developer
1
Chrome Developer Center
1
chrome developer summit
1
chrome devtools
1
Chrome extension
1
chrome extensions
3
Chrome Frame
1
Chrome lite
1
Chrome on Android
2
chrome on ios
1
Chrome on Mac
1
Chrome OS
1
chrome privacy
4
chrome releases
1
chrome security
10
chrome web store
32
chromedevtools
1
chromeframe
3
chromeos
4
chromeos.dev
1
chromium
9
cloud print
1
coalition
1
coalition for better ads
1
contact picker
1
content indexing
1
cookies
1
core web vitals
2
csrf
1
css
1
cumulative layout shift
1
custom tabs
1
dart
8
dashboard
1
Data Saver
3
Data saver desktop extension
1
day 2
1
deceptive installation
1
declarative net request api
1
design
2
developer dashboard
1
Developer Program Policy
2
developer website
1
devtools
13
digital event
1
discoverability
1
DNS-over-HTTPS
4
DoH
4
emoji
1
emscriptem
1
enterprise
1
extensions
27
Fast badging
1
faster web
1
features
1
feedback
2
field data
1
first input delay
1
Follow
1
fonts
1
form controls
1
frameworks
1
fugu
2
fund
1
funding
1
gdd
1
google earth
1
google event
1
google io 2019
1
google web developer
1
googlechrome
12
harmful ads
1
html5
11
HTTP/3
1
HTTPS
4
iframes
1
images
1
incognito
1
insecure forms
1
intent to explain
1
ios
1
ios Chrome
1
issue tracker
3
jank
1
javascript
5
lab data
1
labelling
1
largest contentful paint
1
launch
1
lazy-loading
1
lighthouse
2
linux
2
Lite Mode
2
Lite pages
1
loading interventions
1
loading optimizations
1
lock icon
1
long-tail
1
mac
1
manifest v3
2
metrics
2
microsoft edge
1
mixed forms
1
mobile
2
na
1
native client
8
native file system
1
New Features
5
notifications
1
octane
1
open web
4
origin trials
2
pagespeed insights
1
pagespeedinsights
1
passwords
1
payment handler
1
payment request
1
payments
2
performance
20
performance tools
1
permission UI
1
permissions
1
play store
1
portals
3
prefetching
1
privacy
2
privacy sandbox
4
private prefetch proxy
1
profile guided optimization
1
progressive web apps
2
Project Strobe
1
protection
1
pwa
1
QUIC
1
quieter permissions
1
releases
3
removals
1
rlz
1
root program
1
safe browsing
2
Secure DNS
2
security
36
site isolation
1
slow loading
1
sms receiver
1
spam policy
1
spdy
2
spectre
1
speed
4
ssl
2
store listing
1
strobe
2
subscription pages
1
suspicious site reporter extension
1
TCP
1
the fast and the curious
23
TLS
1
tools
1
tracing
1
transparency
1
trusted web activities
1
twa
2
user agent string
1
user data policy
1
v8
6
video
2
wasm
1
web
1
web apps
1
web assembly
2
web developers
1
web intents
1
web packaging
1
web payments
1
web platform
1
web request api
1
web vitals
1
web.dev
1
web.dev live
1
webapi
1
webassembly
1
webaudio
3
webgl
7
webkit
5
WebM
1
webmaster
1
webp
5
webrtc
6
websockets
5
webtiming
1
writable-files
1
yerba beuna center for the arts
1
Archive
2024
dic
ago
giu
mag
apr
mar
feb
2023
nov
ott
set
ago
giu
mag
apr
feb
2022
dic
set
ago
giu
mag
apr
mar
feb
gen
2021
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2020
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2019
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2018
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2017
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2016
dic
nov
ott
set
ago
giu
mag
apr
mar
feb
gen
2015
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2014
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2013
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2012
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2011
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2010
dic
nov
ott
set
ago
lug
giu
mag
apr
mar
feb
gen
2009
dic
nov
set
ago
lug
giu
mag
apr
mar
feb
gen
2008
dic
nov
ott
set
Feed
Follow @ChromiumDev
Give us feedback in our
Product Forums
.
