What features are supported or unsupported in pdfHTML?

This FAQ provides a detailed overview of the support for PDF standards and HTML and CSS features in the pdfHTML add-on for iText Core. It is intended to help developers understand the current capabilities and limitations of pdfHTML when generating PDF documents from HTML content.

The information presented here is based on the feature set available in pdfHTML 6.2.0, released with iText Core 9.2.0. This document will be updated to reflect any changes, enhancements, and newly supported features in future releases.

You can also use the HTML Converter app in the iText Demo Lab if you're unsure whether specific HTML or CSS features are supported. This demo is built using the latest release version of pdfHTML, so it always reflects the most up-to-date capabilities.

PDF Standards Support

Our implementation supports converting HTML documents to PDF files compliant with PDF/UA-1, PDF/UA-2, as well as PDF/A standards (including PDF/A-1, PDF/A-2, PDF/A-3, and PDF/A-4). This ensures the generation of documents that meet modern requirements for both accessibility and long-term archiving.

HTML tags currently supported by pdfHTML

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HTML5 Tag	Supported	Description
<!--...-->	❌	Defines a comment
<!DOCTYPE>	❌	Defines the document type
<a>	✅	Defines a hyperlink
<abbr>	✅	Defines an abbreviation or an acronym
<address>	✅	Defines contact information for the author/owner of a document
<applet>	❌	Not supported in HTML5. Use `<embed>` or `<object>` instead. Defines an embedded applet
<area>	❌	Defines an area inside an image-map
<article>	✅	Defines an article
<aside>	✅	Defines content aside from the page content
<audio>	❌	Defines sound content
<b>	✅	Defines bold text
<base>	❌	Specifies the base URL/target for all relative URLs in a document
<basefont>	❌	Not supported in HTML5. Use CSS instead. Specifies a default color, size, and font for all text in a document
<bdi>	✅	Isolates a part of text that might be formatted in a different direction from other text outside it
<bdo>	❌	Overrides the current text direction
<blockquote>	✅	Defines a section that is quoted from another source
<body>	✅	Defines the document's body
<br>	✅	Defines a single line break
<button>	✅	Defines a clickable button
<canvas>	✅	Used to draw graphics, on the fly, via scripting (usually JavaScript)
<caption>	✅	Defines a table caption
<cite>	✅	Defines the title of a work
<code>	✅	Defines a piece of computer code
<col>	✅	Specifies column properties for each column within a `<colgroup>` element
<colgroup>	✅	Specifies a group of one or more columns in a table for formatting
<datalist>	❌	Specifies a list of pre-defined options for input controls
<dd>	✅	Defines a description/value of a term in a description list
<del>	✅	Defines text that has been deleted from a document
<details>	❌	Defines additional details that the user can view or hide
<dfn>	✅	Represents the defining instance of a term
<dialog>	❌	Defines a dialog box or window
<div>	✅	Defines a section in a document
<dl>	✅	Defines a description list
<dt>	✅	Defines a term/name in a description list
<em>	✅	Defines emphasized text
<embed>	❌	Defines a container for an external (non-HTML) application
<fieldset>	❌	Groups related elements in a form
<figcaption>	✅	Defines a caption for a `<figure>` element
<figure>	✅	Specifies self-contained content
<footer>	✅	Defines a footer for a document or section
<form>	✅	Defines an HTML form for user input
<h1> to <h6>	✅	Defines HTML headings
<head>	✅	Defines information about the document
<header>	✅	Defines a header for a document or section
<hr>	✅	Defines a thematic change in the content
<html>	✅	Defines the root of an HTML document
<i>	✅	Defines a part of text in an alternate voice or mood
<iframe>	❌	Defines an inline frame
<img>	✅	Defines an image
<input>	✅	Defines an input control
<ins>	✅	Defines a text that has been inserted into a document
<kbd>	✅	Defines keyboard input
<keygen>	❌	Defines a key-pair generator field (for forms)
<label>	✅	Defines a label for an `<input>` element
<legend>	✅	Defines a caption for a `<fieldset>` element
<li>	✅	Defines a list item
<link>	✅	Defines the relationship between a document and an external resource (most used to link to style sheets)
<main>	✅	Specifies the main content of a document
<map>	❌	Defines a client-side image-map
<mark>	✅	Defines marked/highlighted text
<menu>	❌	Defines a list/menu of commands
<menuitem>	❌	Defines a command/menu item that the user can invoke from a popup menu
<meta>	✅	Defines metadata about an HTML document
<meter>	❌	Defines a scalar measurement within a known range (a gauge)
<nav>	✅	Defines navigation links
<noscript>	❌	Defines an alternate content for users that do not support client-side scripts
<object>	❌ We support only SVG content	Defines an embedded object
<ol>	✅	Defines an ordered list
<optgroup>	✅	Defines a group of related options in a drop-down list
<option>	✅	Defines an option in a drop-down list
<output>	❌	Defines the result of a calculation
<p>	✅	Defines a paragraph
<pre>	✅	Defines preformatted text
<progress>	❌	Represents the progress of a task
<q>	✅	Defines a short quotation
<rp>	❌	Defines what to show in browsers that do not support ruby annotations
<rt>	❌	Defines an explanation/pronunciation of characters (for East Asian typography)
<ruby>	❌	Defines a ruby annotation (for East Asian typography)
<s>	✅	Defines text that is no longer correct
<samp>	✅	Defines sample output from a computer program
<script>	❌	Defines a client-side script
<section>	✅	Defines a section in a document
<select>	✅	Defines a drop-down list
<small>	✅	Defines smaller text
<source>	❌	Defines multiple media resources for media elements (`<video>` and `<audio>`)
<span>	✅	Defines a section in a document
<strong>	✅	Defines important text
<style>	✅	Defines style information for a document
<sub>	✅	Defines subscripted text
<summary>	❌	Defines a visible heading for a `<details>` element
<sup>	✅	Defines superscripted text
<table>	✅	Defines a table
<tbody>	❌	Groups the body content in a table
<td>	✅	Defines a cell in a table
<textarea>	✅	Defines a multiline input control (text area)
<tfoot>	✅	Groups the footer content in a table
<th>	✅	Defines a header cell in a table
<thead>	✅	Groups the header content in a table
<time>	✅	Defines a date/time
<title>	✅	Defines a title for the document
<tr>	✅	Defines a row in a table
<track>	❌	Defines text tracks for media elements (`<video>` and `<audio>`)
<u>	✅	Defines text that should be stylistically different from normal text
<ul>	✅	Defines an unordered list
<var>	✅	Defines a variable
<video>	❌	Defines a video or movie
<wbr>	❌	Defines a possible line-break

CSS modules currently supported by pdfHTML

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CSS backgrounds and borders

Property	Supported
background-attachment	❌
background-clip	✅
background-color	✅
background-image	✅
background-origin	✅
background-position	✅
background-repeat	✅
background-size	✅
background	✅
background-position-x	✅
background-position-y	✅
border-bottom-color	✅
border-bottom-style	✅
border-bottom-width	✅
border-bottom	✅
border-left-color	✅
border-left-style	✅
border-left-width	✅
border-left	✅
border-right-color	✅
border-right-style	✅
border-right-width	✅
border-right	✅
border-top-color	✅
border-top-style	✅
border-top-width	✅
border-top	✅
border-color	✅
border-style	✅
border-width	✅
border	✅
border-bottom-left-radius	✅
border-bottom-right-radius	✅
border-top-left-radius	✅
border-top-right-radius	✅
border-radius	✅
border-image-outset	❌
border-image-repeat	❌
border-image-slice	❌
border-image-source	❌
border-image-width	❌
border-image	❌
box-shadow	❌

CSS basic user interface

Property	Supported
accent-color	❌
appearance	❌
caret	❌
caret-color	❌
caret-shape	❌
cursor	❌
nav-down	❌
nav-left	❌
nav-right	❌
nav-up	❌
outline	✅
outline-color	✅
outline-style	✅
outline-width	✅
outline-offset	✅
pointer-events	❌
resize	❌
user-select	❌

CSS fonts

Property	Supported
font	✅
font-family	✅
font-feature-settings	❌
font-kerning	❌
font-language-override	❌
font-optical-sizing	❌
font-palette	❌
font-size	✅
font-size-adjust	❌
font-stretch	❌
font-style	✅
font-weight	✅
font-synthesis	❌
font-synthesis-position	❌
font-synthesis-small-caps	❌
font-synthesis-style	❌
font-synthesis-weight	❌
font-variant	❌
font-variant-alternates	❌
font-variant-caps	❌
font-variant-east-asian	❌
font-variant-emoji	❌
font-variant-ligatures	❌
font-variant-numeric	❌
font-variant-position	❌
font-variation-settings	❌

CSS box alignment

Property	Supported
align-content	✅
align-items	✅
align-self	❌ Supported for flex
column-gap	✅
gap	✅
justify-content	❌ Supported for flex
justify-items	❌
justify-self	❌
place-content	❌
place-items	❌
place-self	❌
row-gap	✅

CSS box model

Property	Supported
margin	✅
margin-bottom	✅
margin-left	✅
margin-right	✅
margin-top	✅
margin-trim	✅
padding	✅
padding-bottom	✅
padding-left	✅
padding-right	✅
padding-top	✅

CSS box sizing

Property	Supported
aspect-ratio	❌
box-sizing	✅
contain-intrinsic-block-size	❌
contain-intrinsic-height	❌
contain-intrinsic-inline-size	❌
contain-intrinsic-size	❌
contain-intrinsic-width	❌
height	✅
max-height	✅
max-width	✅
min-height	✅
min-width	✅
width	✅

CSS colors

Property	Supported
color	✅
opacity	✅

CSS compositing and blending

Property	Supported
background-blend-mode	✅
isolation	❌
mix-blend-mode	❌

CSS display

Property	Supported
display	✅
order	✅ for flex ❌ for grid
visibility	❌
reading-flow	❌
reading-order	❌
float	✅

CSS filter effects

Property	Supported
backdrop-filter	❌
filter	❌

CSS flexible box layout

Property	Supported
align-content	✅
align-items	✅
align-self	✅
flex	✅
flex-basis	✅
flex-direction	✅
flex-flow	✅
flex-grow	✅
flex-shrink	✅
flex-wrap	✅
justify-content	✅

CSS fragmentation

Property	Supported
box-decoration-break	❌
break-after	❌
break-before	❌
break-inside	❌
orphans	✅
widows	✅

CSS generated content

Property	Supported
content	✅
quotes	✅

CSS grid layout

Property	Supported
grid-auto-columns	✅
grid-auto-flow	✅
grid-auto-rows	✅
grid-template-columns	✅
grid-template-rows	✅
grid-template-areas	✅
grid-template	✅
grid	✅
grid-column-start	✅
grid-column-end	✅
grid-column	✅
grid-row-start	✅
grid-row-end	✅
grid-row	✅
grid-area	✅

CSS images

Property	Supported
image-orientation	❌
image-rendering	❌
image-resolution	❌
object-fit	✅
object-position	❌

CSS inline layout

Property	Supported
alignment-baseline	❌
dominant-baseline	❌
initial-letter	❌
line-height	✅
text-box-edge	❌
text-box-trim	❌
text-box	❌
vertical-align	✅

CSS lists and counters

Property	Supported
counter-increment	✅
counter-reset	✅
counter-set	❌
list-style-image	✅
list-style-type	✅
list-style-position	✅
list-style	✅

CSS media queries

This module contains @import and @media rules that we support

CSS motion path

Property	Supported
offset	✅
offset-anchor	❌
offset-distance	❌
offset-path	❌
offset-position	❌
offset-rotate	❌

CSS multi-column layout

Property	Supported
break-after	❌
break-before	❌
break-inside	❌
column-fill	❌
column-gap	❌
column-span	❌
column-rule	✅
column-rule-color	✅
column-rule-style	✅
column-rule-width	✅
columns	✅
column-count	✅
column-width	✅

CSS nesting

This module is broadly supported, however, you may experience issues with nesting tags relating to image alignment, font sizes, or inline tables.

CSS paged media

We support only a @page rule not a page property.

CSS positioned layout

Property	Supported
top	✅
right	✅
bottom	✅
left	✅
inset	❌
inset-inline	❌
inset-inline-start	❌
inset-inline-end	❌
inset-block	❌
inset-block-start	❌
inset-block-end	❌
position	✅
z-index	❌
overlay	❌

CSS pseudo-elements

Selectors	Supported
::after	✅
::before	✅
::file-selector-button	❌
::first-letter	❌
::first-line	❌
::grammar-error	❌
::highlight()	❌
::marker	❌
::placeholder	✅
::selection	❌
::spelling-error	❌
::target-text	❌

CSS selectors

We support the following selectors: empty, first-child, first-of-type, last-child, last-of-type, not, nth-child(), nth-of-type(), nth-last-child(), nth-last-of-type().

CSS table

Property	Supported
border-collapse	✅
border-spacing	✅
caption-side	✅
empty-cells	❌
table-layout	❌

CSS text color

Property	Supported
hanging-punctuation	❌
hyphenate-character	❌
hyphenate-limit-chars	❌
hyphens	✅
letter-spacing	✅
line-break	❌
overflow-wrap (and the word-wrap alias)	✅
tab-size	❌
text-align	✅
text-align-last	❌
text-indent	✅
text-justify	❌
text-spacing-trim (Experimental)	❌
text-transform	✅
text-wrap	❌
text-wrap-mode	❌
text-wrap-style	❌
white-space	✅
white-space-collapse	❌
word-break	✅
word-spacing	✅

CSS text decoration

Property	Supported
text-decoration	✅
text-decoration-color	✅
text-decoration-line	✅
text-decoration-skip	❌
text-decoration-skip-ink	❌
text-decoration-style	❌
text-decoration-thickness	❌
text-emphasis	❌
text-emphasis-color	❌
text-emphasis-position	❌
text-emphasis-style	❌
text-shadow	❌
text-underline-offset	❌
text-underline-position	❌

CSS writing modes

Property	Supported
direction	✅
text-combine-upright	❌
text-orientation	❌
unicode-bidi	❌
writing-mode	❌

CSS modules currently unsupported by pdfHTML

The following list contains modules which are either not supported by pdfHTML, or are only partially implemented:

Modules not applicable to PDF rendering

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CSS animations
CSS transitions
CSS scroll-driven animations
CSS scroll snap
CSS scroll anchoring
CSS overscroll behavior
CSS scrollbars styling
CSSOM view
CSS shadow parts
CSS shapes
CSS anchor positioning
CSS values and units (many are dynamic or viewport-relative)

Modules unsupported by the PDF specification

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These modules rely on browser or runtime features that PDF does not support:

CSS masking
CSS namespaces
CSS ruby layout
CSS containment
CSS logical properties and values (except block-size)
CSS transforms (only transform property is partially supported)
CSS custom properties for cascading variables
CSS properties and values API
CSS color adjustment
CSS conditional rules
CSS scoping

Modules not yet implemented or partially supported

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The following may be technically feasible but are not yet fully supported in pdfHTML:

CSS cascading and inheritance (only all property supported)
CSS counter styles (no properties implemented)
CSS overflow (only overflow property is partially supported)