HTML Tag Attribute

Supported Values

background-clip

border-box, padding-box, content-box

background-color

any applicable value

background-origin

border-box, padding-box, content-box

background-position

any applicable value

background-position-x

px,pt,cm,mm,em,rem,ex,%,in

background-position-y

px,pt,cm,mm,em,rem,ex,%,in

background-repeat

any applicable value

background-repeat-x

any applicable value

background-repeat-y

any applicable value

background-size

contain, cover, initial, inherit, px, pt, cm, mm, em, ex, %, in

background-sizex

px, pt, cm, mm, em, ex, %, in, rem

background-sizey

px, pt, cm, mm, em, ex, %, in, rem

border-bottom-color

any applicable value

border-bottom-leftradius

pt, px, cm, %, ex, in, mm, em, rem

border-bottom-rightradius

in, px, ex, pt, %, em, cm, mm, rem

border-bottom-style

hidden, solid, dotted, dashed, double, ridge, groove, inset, outset, none

border-bottom-width

mm, in, ex, px, pt, em, cm, rem,initial

border-collapse

collapse, separate

border-color

any applicable value

border-left-color

any applicable value

border-left-style

hidden, solid, dotted, dashed, double, ridge, groove, inset, outset, none

border-left-width

mm, in, ex, px, pt, em, cm, rem, initial

border-right-color

any applicable value

border-right-style

hidden, solid, dotted, dashed, double, ridge, groove, inset, outset, none

border-right-width

mm, in, ex, px, pt, em, cm, rem, initial

border-style

hidden, solid, dotted, dashed, double, ridge, groove, inset, outset, none

border-top-color

any applicable value

border-top-left-radius

pt, px, ex, cm, mm, em, %, in

border-top-right-radius

%, cm, em, pt, ex, px, in, mm, none

border-top-style

hidden, solid, dotted, dashed, double, ridge, groove, inset, outset, none

border-top-width

mm, in, ex, px, pt, em, cm, rem, initial

border-vertical-spacing

mm, in, ex, em, cm, px, pt, %

border-width

mm, in, ex, px, pt, em, cm, rem, initial

box-align

right, left, center

box-shadow

any applicable value

box-sizing

border-box, padding-box, content-box

break-after

always, auto, avoid

break-before

always, auto, avoid

break-inside

always, auto, avoid

caption-side

top

clear

left, right, both, none

color

any applicable value

column-rule-color

any applicable value

dir

rtl, ltr

display

inline, block, flex, inline flex, table cell, inherit, listitem

empty-cells

hide

float

left, right, snap-block

font-family

any applicable value

font-size

mm, in, ex, em, rem, cm, px, pt, %

font-style

normal, italic, oblique

font-variant

normal, small-caps

font-weight

100, 200, 300, 400, 500, 600, 700, 800, 900, normal, bold, bolder, lighter

height

mm, in, ex, em, cm, px, pt, %, rem

hyphens

auto, manual

letter-spacing

normal, mm, in, ex, em, rem, cm, px, pt, initial

line-height

normal, mm, in, em, cm, px, pt, %, rem

list-style-position

outside, inside, initial

list-style-type

decimal, disc, circle, inherit, initial, lower-alpha, lower-latin, lower-roman, none, upper-alpha, upper-latin, upper-roman, square

margin

mm, in, em, cm, px, pt, %, rem, ex

margin-after

mm, in, em, cm, px, pt, %, rem

margin-before

mm, in, em, cm, px, pt, %, rem

margin-bottom

mm, in, em, cm, px, pt, %, rem, ex

margin-left

mm, in, em, cm, px, pt, %, rem, ex

margin-right

mm, in, em, cm, px, pt, %, rem, ex

margin-top

mm, in, em, cm, px, pt, %, rem, ex

min-height

mm, in, em, cm, px, pt, %, rem

opacity

any applicable value

outline-color

any applicable value

outline-offset

mm, in, ex, em, cm, px, pt, %

outline-style

solid, dotted, dashed, double, ridge, none

outline-width

mm, in, ex, em, cm, px, pt, %

overflow

hidden

overflow-x

hidden

overflow-y

hidden

padding

mm, in, em, cm, px, pt, %, rem, ex

padding-bottom

mm, in, em, cm, px, pt, %, rem, ex

padding-left

mm, in, em, cm, px, pt, %, rem, ex

padding-right

mm, in, em, cm, px, pt, %, rem, ex

padding-top

mm, in, em, cm, px, pt, %, rem, ex

page-break-after

left, right, always, auto, avoid

page-break-before

left, right, always, auto, avoid

page-break-inside

always, auto, avoid

ruby-align

start, center, space-around, space-between

ruby-position 

over

text-align

left, right, center, justify

text-combine-upright

all

text-decoration

line-through, overline, underline

text-fill-color

any applicable value

text-indent

mm, in, ex, em, cm, px, pt, %, rem

text-shadow

any applicable value

text-stroke-color

any applicable value

text-transform

lowercase, uppercase, capitalize, none

transform

any applicable value

unicode-bidi

bidi-override, normal, embed, initial, isolate, isolateoverride & plaintext

vertical-align

sub, super, top, text-top, middle, bottom, text-bottom, baseline, mm, in, ex, px, pt, em, cm, % , rem , center

visibility

visible, hidden, initial

-webkit-text-emphasis-style

any applicable value

-webkit-text-emphasis-color

any applicable value

-webkit-text-emphasis-position

over, under

-webkit-text-orientation

mixed, upright, sideways, sideways-right

white-space

nowrap, normal

width

auto, mm, in, ex, em, cm, px, pt, %, rem

word-break

normal, keep-all, break-all

word-spacing

normal, mm, in, ex, em, rem, cm, px, pt, initial

writing-mode

horizontal-tb, vertical-rl

HTML Tag

HTML Attribute

Supported Values

a

epub:type, data-app-amznmagnify, href

noteref

address

any applicable attribute

any applicable value

aside

epub:type

footnote

b

any applicable attribute

any applicable value

background-size

any applicable value

any applicable value

bdi

any applicable attribute

any applicable value

bdo

any applicable attribute

any applicable value

blockquote

any applicable attribute

any applicable value

body

bgcolor

any applicable value

body

text

any applicable value

caption

align

center, justify

center

any applicable attribute

any applicable value

cite

any applicable attribute

any applicable value

code

any applicable attribute

any applicable value

col

span

any applicable value

col

width

%, px

dd

any applicable attribute

any applicable value

del

any applicable attribute

any applicable value

div

align

center, left, right, justify

div

epub:type

footnote

dl

any applicable attribute

any applicable value

em

any applicable attribute

any applicable value

figure

any applicable attribute

any applicable value

h1

align

center, left, right, justify

h2

align

center, left, right, justify

h3

align

center, left, right, justify

h4

align

center, left, right, justify

h5

align

center, left, right, justify

h6

align

center, left, right, justify

hr

align

center, left, right

hr

noshade

any applicable value

hr

size

px

hr

width

px, %

i

any applicable attribute

any applicable value

image

height

%, px, em, pt

image

width

%, px, em, pt

img

align

center, middle, top, bottom, absbottom, absmiddle

img

alt

any applicable value

img

border

px, pt, cm, mm, em, rem, ex, in, %

img

height

%, px, em, pt

img

hspace

px

img

vspace

px

img

width

%, px, em, pt

li

type

a, i, disc, square, circle, none, A, I

li

value

any applicable value

listing

any applicable attribute

any applicable value

mark

any applicable attribute

any applicable value

ol

start

any applicable value

ol

type

a, i, none, A, I

p

align

center, left, right, justify

p

epub:type

footnote

plaintext

any applicable attribute

any applicable value

pre

any applicable attribute

any applicable value

rb

any applicable attribute

any applicable value

rt

any applicable attribute

any applicable value

ruby

any applicable attribute

any applicable value

s

any applicable attribute

any applicable value

samp

any applicable attribute

any applicable value

strike

any applicable attribute

any applicable value

strong

any applicable attribute

any applicable value

table

align

center, left, right

table

bgcolor

any applicable value

table

width

%, px

tbody

align

center, left, right, justify

td

align

center, left, right, justify

td

bgcolor

any applicable value

td

colspan

any applicable value

td

height

%, px

td

rowspan

any applicable value

td

vertical-align

center, middle, top, bottom

td

width

%, px

tfoot

align

center, left, right, justify

th

align

center, left, right, justify

th

bgcolor

any applicable value

th

colspan

any applicable value

th

height

%, px

th

rowspan

any applicable value

th

vertical-align

center, middle, top, bottom

th

Width

%, px

thead

Align

center, left, right, justify

thead

Bgcolor

any applicable value

tr

Align

center, left, right, justify

tr

Bgcolor

any applicable value

tt

any applicable attribute

any applicable value

ul

any applicable attribute

any applicable value

var

any applicable attribute

any applicable value

xmp

any applicable attribute

any applicable value

webkit-background-size

any applicable value

any applicable value

1. Open all the HTML present in source EPUB using any text editor.
2. Open the navigation html (TOC.xhtml/Nav.xhtml) inside source EPUB.
3. Validate if ID present after HTML name in href attribute of anchor tag is present in body tag of source HTML.
4. Move the ids present in the parent body tag to child div tag.
5. Follow the same for all the instances, zip the contents, and save it as EPUB file.

1. Open all the HTML present in source EPUB using any text editor.
2. Open the navigation html (TOC.xhtml/Nav.xhtml) inside source EPUB.
3. Validate if ID present after html name in href attribute of anchor tag is directing to a source HTML tag with style="display:none" or style="visibility:hidden"
4. Move the ids present in the respective Source HTML tag to another tag without display:none or visibility:hidden
5. Follow the same for all the instances, zip the contents, and save it as EPUB file.

1. Open the NCX file using any text editor.
2. Reduce the number of levels created using unordered list or ordered list tags up to 2 levels.
3. Zip the contents and preview the source in kindle previewer before publishing

1. Open all the CSS and HTML files using any Text editor.
2. Search for display:none css style in all HTML.
3. Make sure to limit the usage of display:none style to less that 10000 characters.
4. Recreate the source HTML with limited usage of display:none
5. Preview the content using Kindle Previewer before publishing

1. Open the OPF file using any text editor.
2. Verify if dc:title is declared more than once in metadata content of the OPF file.
3. Declare the "title-type" as "main" title for either one of declaration presented in OPF file.
4. Zip the contents and preview the final file using Kindle Previewer.

1. Open the OPF file using any text editor.
2. Verify if the OPF file is structured as per the IDPF standard and all tags are closed properly.
3. Make sure the OPF is structured as Package declaration, Metadata, manifest, spine and guide tags.
4. Zip the contents and preview the final file using Kindle Previewer.

1. Open the OPF file using any text editor.
2. Validate if the id present in cover image declaration in manifest tag is same as the content attribute value of cover declaration in OPF file.
3. If both are different, change the id or content attribute to ensure both are same.
4. Zip the contents and preview the final file using Kindle Previewer.

HTML Tag Attribute

Unsupported Values

Alternative Value or Option

background-image

linear gradient

Use a media query to specify a replacement, such as the background-color property. Reupload your corrected file for publication or retry the corrected file in Kindle Previewer.

Base64 encoded images

not applicable

Use an online tool to decode the Base64 image and provide it as a normal binary image file.

body, within Table of Contents HTML file

display: none, hidden

Remove display: none or hidden values from ToC HTML file.

caption-side

bottom

Content styled with <caption-side: bottom> will be positioned at the top of the table like <caption-side:top>.

float, within a table

left, right

Use a media query to specify a replacement for Kindle using the CSS ::first-letter Selector.

SVG

namespace prefix

Remove the SVG namespace prefix from SVG element(s) within the file.

video

any applicable value

Please visit Creating Kindle Editions with Audio/Video Content for video support options on Kindle.

visibility

collapse

When using this tag within a table, use display:none to achieve a similar reading experience. When using this tag outside of a table, use visibility:hidden.

HTML Tag

Style Attribute

a

rel, rev, shape, name, target, type

applet

hspace, height, name, width, vspace, align, alt

background-image

linear gradient

body

bottommargin, link, rightmargin, vlink

button

value, name, type

caption-side

bottom

display;

table-column-group;table-column;table-caption

div

node-type, type

frame

name

frameset;

rows

html

xmlns, encoding, version

iframe

name, align, width, height

image

xlink:href

img

hspace

input

align

link

type, media, rel, href

meta

name, http-equiv

object

name, width, hspace, align, type, border, vspace, height

param

value, type, name

script

type, for

style

type, media

text-decoration

line-through, overline, underline, Underline solid,underline dotted,underline dashed,underline double,overline solid,overline dotted,overline dashed,overline double,line-through solid,,line-through dotted,line-through dashed,,line-through double,underline line-through,line-through underline,underline overline,line-through overline,overline line-through,overline underline,overline line-through underline,overline underline line-through,underline overline line-through,underline line-through overline,line-through overline underline,line-through underline overline,none