To prevent certain security exploits, Looker restricts which HTML tags, HTML tag attributes, and CSS properties are allowed in the html parameter, in custom welcome emails, and in text tiles and tile notes in dashboards.
Looker strips any HTML elements that aren't supported from the rendered HTML. For example, the following HTML has unsupported HTML tags:
<div class="pretty"><badtag></badtag></div>
Looker will render this as:
<div class="pretty"></div>
As another example, the following HTML has unsupported HTML attributes:
<div class="pretty" badattr="uh-oh"></div>
Looker will render this as:
<div class="pretty"></div>
HTML sanitization is on by default and can't be edited.
Allowed HTML tags
Only certain HTML tags will be rendered in the browser. Any other tags will be stripped from rendered HTML.
Here is the list of HTML tags that Looker supports:
a
abbr
acronym
address
area
article
aside
audio
b
bdi
bdo
big
blockquote
br
button
canvas
caption
center
cite
code
col
colgroup
datalist
dd
del
details
dfn
dir
div
dl
dt
em
fieldset
figcaption
footer
h1
h2
h3
h4
h5
h6
header
ins
hr
i
img
kbd
label
legend
li
map
mark
menu
meter
nav
ol
output
p
pre
q
s
samp
section
small
source
span
strike
strong
sub
summary
sup
table
tbody
td
tfoot
th
thead
time
tr
track
tt
u
ul
var
video
Allowed HTML tag attributes
Only certain HTML attributes will be rendered in the browser. Any other attributes will be stripped from rendered HTML. This also applies to the CSS properties for HTML style tags.
Here is the list of HTML attributes that Looker supports:
abbr
accept
accept-charset
accesskey
action
align
alt
autoplay
axis
border
cellpadding
cellspacing
char
charoff
charset
checked
cite
class
clear
color
cols
colspan
compact
controls
controlslist
coords
datetime
dir
disabled
enctype
for
frame
headers
height
href
hreflang
hspace
id
ismap
label
lang
longdesc
loop
loopcount
loopend
loopstart
maxlength
media
method
multiple
muted
name
nohref
noshade
nowrap
poster
preload
prompt
readonly
rel
rev
rows
rowspan
rules
scope
selected
shape
size
span
src
start
style
summary
tabindex
target
title
type
usemap
valign
value
vspace
width
xml:lang
Allowed CSS Properties for HTML style Tags
Here is the list of allowed CSS properties that Looker supports:
-moz-border-radius
-moz-border-radius-bottomleft
-moz-border-radius-bottomright
-moz-border-radius-topleft
-moz-border-radius-topright
-moz-box-shadow
-moz-outline
-moz-outline-color
-moz-outline-style
-moz-outline-width
-o-text-overflow
-webkit-border-bottom-left-radius
-webkit-border-bottom-right-radius
-webkit-border-radius
-webkit-border-radius-bottom-left
-webkit-border-radius-bottom-right
-webkit-border-radius-top-left
-webkit-border-radius-top-right
-webkit-border-top-left-radius
-webkit-border-top-right-radius
-webkit-box-shadow
azimuth
background
background-attachment
background-color
background-image (note that url is unsupported)
background-position
background-repeat
border
border-bottom
border-bottom-color
border-bottom-left-radius
border-bottom-right-radius
border-bottom-style
border-bottom-width
border-collapse
border-color
border-left
border-left-color
border-left-style
border-left-width
border-radius
border-right
border-right-color
border-right-style
border-right-width
border-spacing
border-style
border-top
border-top-color
border-top-left-radius
border-top-right-radius
border-top-style
border-top-width
border-width
box-shadow
caption-side
clear
color
cue
cue-after
cue-before
cursor
direction
display
elevation
empty-cells
float
font
font-family
font-size
font-stretch
font-style
font-variant
font-weight
height
image()
letter-spacing
line-height
linear-gradient()
list-style
list-style-image
list-style-position
list-style-type
margin
margin-bottom
margin-left
margin-right
margin-top
max-height
max-width
min-height
min-width
outline
outline-color
outline-style
outline-width
overflow
padding
padding-bottom
padding-left
padding-right
padding-top
pause
pause-after
pause-before
pitch
pitch-range
quotes
radial-gradient()
rect()
repeating-linear-gradient()
repeating-radial-gradient()
rgb()
rgba()
richness
speak
speak-header
speak-numeral
speak-punctuation
speech-rate
stress
table-layout
text-align
text-decoration
text-indent
text-overflow
text-shadow
text-transform
text-wrap
unicode-bidi
vertical-align
voice-family
volume
white-space
width
word-spacing
word-wrap