
Recommended Software Tools to
Tag, Create, Validate and Remediate/Correct PDF files for
Compliance with the ISO Standard 14289, PDF/UA,
for Universally Accessible PDF
Best approach to create Accessible PDF, direct or indirect?
In principle, universally accessible PDF documents can either be
generated directly during document creation, using a suitable program,
or indirectly generated by adapting an existing PDF document.
The indirect approach tends to require a great deal of work,
as all tags and numerous other settings will need to be provided manually.
This work can also become void as soon as a new version of the PDF document
replaces the old one, if any changes to the document’s content need to be made.
The adaptation process must then be started again from scratch.
The direct approach is almost always the better option;
post-creation PDF edits should be avoided or at least kept to a minimum.
Either way, it is essential that the document creation program can perform
the functions required and that the document creator can make use of them.

Why not solely use the well-known software tools
Microsoft Office, Adobe InDesign, Adobe Acrobat,...
to create, validate or read Accessible PDF?
It is not the assistive technologies, nor popular software tools
such as MS Office with Microsoft Office Accessibility Checker,
Adobe InDesign, Adobe Acrobat with Adobe Acrobat Accessibility Checker,
Google Docs, Apple iWork,... or screen/text readers like
JAWS, NVDA, MS Narrator, Apple VoiceOver,...
that define what is an accessible PDF.
A PDF document is defined as "accessible PDF" only when it
meets the ISO Standard PDF/UA with guidelines,
and applicable parts of the WCAG 2.1 AA recommendations!
Currently, the above mentioned software tools,
which are used by many users to create and edit PDF documents,
are usually not sufficiently "PDF/UA-Ready";
they lack the ability to always correctly export a final PDF document
according to PDF/UA and they do not validate well enough
to comply with the PDF/UA standard.
The exported PDF file thus risks not being "accessible PDF" nor meet
accessibility requirements under the EU Web Accessibility Directive or
the Swedish Act on Accessibility to Digital Public Services for everyone!
Just because you tag a PDF document with Adobe Acrobat or MS Office
and the file then pass the check with
- Adobe Acrobat Accessibility Checker, or with
- Microsoft Office Accessibility Checker
the PDF file can still have severe accessibility errors,
especially if the file contains data tables or other complex structures.
So don't expect too much from these control features for now.
Note! Adobe Acrobat Accessibility Checker!
In Adobe Acrobat it is recommended to use
Adobe Acrobat Accessibility Checker for compliance checking
against current standards for digital accessibility,
but unfortunately it is completely misleading.
It gives the impression that Adobe Acrobat Accessibility Checker
performs a very comprehensive and thorough checking for compliance
with all globally recognized digital accessibility standards,
but it turns out that Adobe Acrobat Accessibility Checker
unfortunately does not perform that check at all!
Adobe Acrobat Checker does not check to any known standard.
It only checks for common issues you are likely to encounter,
but it is not a full check.
There can still be problems with the file that
the Acrobat Checker is not identifying.
The PDF Accessible Checker/PAC (as well as others)
does a full check to the PDF/UA and WCAG standards.
This also explains why most PDF files that pass
Adobe Acrobat Accessibility Checker without remarks
does not meet the technical requirements for accessible PDF:
Instead, this is the preferred method to check for syntax compliance
with the ISO standard PDF/UA in Adobe Acrobat:
- Select feature: "Tools"
- Select feature: "Print production"
- Select feature: "Preflight"
- Select in the top tab: "PDF standards"
- Select in tab "Profiles: PDF/UA compliance,
Verify compliance with PDF/UA-1"
(Worth knowing:
The preflight feature for the PDF/UA check in Adobe Acrobat
is developed by and sourced from callas software.
Not all functionality for controls, adjustments and actions that
callas software develops is included in Adobe Acrobat Preflight.
In general, the preflight features from callas software have
a more frequent update interval than Adobe Acrobat Preflight.
This means that new functions are available earlier in callas products.
For access to the very latest updated and most complete
preflight technology as well as all functions to fix any
syntax problems discovered during preflight,
it is highly recommended that you instead use
callas pdfToolbox, callas pdfaPilot and/or callas pdfGoHTML)
Time is money! - Invest in "PDF/UA-Ready" software tools
The process to build accessible documents is far from always straightforward.
To quickly make something barrier-free by pressing a few buttons
in your ordinary software tool do not usually lead to a successful result.
Strive to minimize the time using software tools that
can not natively export PDF/UA compliant documents.
The part you do in Adobe InDesign or MS Office is like
pouring the foundation of a house:
It’s a critical first step, but there’s a lot more work ahead
(in the form of what is called "PDF remediation") before the job is done.
For this reason, third-party tools and services are available to ease the process.
So, instead of spending endless hours with substandard software tools,
invest a small amount in complementary aids and software tools
that are "PDF/U-Ready".
By using "PDF/UA-Ready" software tools, you significantly shorten
the working time to create accessible PDF.
Tricky use case: Complex data tables
All tables, even complex data tables
(tables with multi-column headers and multi-row headers)
can be designed to be accessible tables in PDF documents.
A typical use case where native Adobe InDesign fails
is tagging of complex data tables.
As of today, Adobe InDesign can not natively export PDF/UA compliant files.
Adobe's recommendation is to first export the PDF-file out of InDesign,
and then in a follow-on step undertake required post-processing fixes in
the PDF-file with Adobe Acrobat Pro DC to make the file PDF/UA compliant.
In theory complex data tables could be tagged in Adobe Acrobat Pro DC,
but it is in practise a cumbersome and very time-consuming process and
requires and consumes an unreasonable number of working hours of your time.
Only a few software tools offer in-built and out of the box
support for tagging of complex data tables in minutes,
or at least with less effort, and thereafter export of PDF/UA
compliant documents, in a significantly shorter time:
"PDF/UA-Ready" software tools
Regardless of what software tool you prefer to use to create accessible PDF,
make sure you really understand how the tool works, because then it is
more flexible and you will get the most out of it.
Users often claim:
"PDF documents are not just accessible as source documents created
in MS Word or Adobe InDesign or something else software tool."
That is just not true!
The problem is that most users who are creating PDFs don't know how to
use the source software tool (MS Word or Adobe InDesign, etc.) properly,
and they aren't incorporating accessibility features into the source file either.
Or they may even export to PDF in a way that negatively affects
the accessibility of the PDF.
The truth is:
It is all in how the source file was set up and
how the PDF document was exported.
Make sure you prepare your source document correctly
because then the exported PDF is going to be pretty accessible.
Questions to ask yourself:
- Do I really understand how the software tool works?
- Did I create my document the way the software tool was intended?
- Did I use the tool the right way?
- Did I use styles?
- Did I use tables to layout my three column layout
rather than actual columns?
- ...and other related questions
"PDF/UA-Ready" software tools has the ability to verify/confirm PDF/UA
conformance based on the Matterhorn Protocol's set of checks.
It is also required that you understand and can apply
requirements for checkpoints and tags according to
the PDF/UA standard
However, to correctly create accessible PDF more is required
than just "PDF/UA-Ready" software tools.
It is also required that you understand and can apply
requirements for checkpoints and tags according to
the PDF/UA standard.
The reality is that PDF remediation isn’t quick, easy, or straightforward.
It also requires skill, knowledge, and experience on your part
in remediating the PDF file.
The more knowledge you have, the more you know about the process,
the easier the process becomes.
Recommended (indispensable) reading for you who want to
know more about how to practically create an accessible PDF.
Book: "Create Accessible PDF Documents,
The Practical Hands-On Manual For Everyday Work"
The main aim of this book is to enable all readers to
create barrier-free documents independently and
as effectively as possible from the usual creation programs.
This includes knowing what an accessible PDF is and
how to prepare your content accordingly,
planning production processes and detailed practical implementation
in the various programs.
Includes a lot of examples and valuable checklists for implementation in
Adobe InDesign and Microsoft Office/LibreOffice.
The book is available to order from dpunkt.verlag
Note! Only available in German
Does the necessary work effort feel overwhelming?
Anything you can use to streamline the process
can significantly change your workflow for the better.
An individual user can probably manually create and manage
a certain limited number of PDF documents, depending on
the number of pages and complexity.
In case of need to create and maintain many hundreds or even
thousands of documents, we highly recommend the use of
solutions that do support large-scale production and
automated workflow processes.
Does the necessary work effort feel overwhelming?
Then we recommend:
"PDF/UA-Ready" software tools, and free trials
For full information on software tools, provided by NewFormat,
that do support accessible PDF (PDF/UA), download of free trials,
tutorials, recorded demonstrations, etc.,
click on the preferred tools/links below.
Tools for creating tags in source files and PDF documents
Software tools with the ability to create tagged PDF documents
with semantically appropriate structure elements from
a source file or existing untagged PDF.
Tagging of PDF documents for compliance with PDF/UA-1.
Recommended guides on to how to correctly tag
PDF documents according to PDF/UA-1:
"PDF/UA-Ready" software tools for TAGGING of PDF documents / Tagged PDF:
axaio MadeToTag for Adobe InDesign
Plugin to Adobe InDesign. For Windows and macOS.
Creates tags according to the PDF/UA Standard.
Significantly speeds up the tagging work in Adobe InDesign!
axesWord for MS Word
Plugin to MS Word for Windows.
Creates tags according to the PDF/UA Standard.
Facilitates the tagging process based on templates.
CommonLook Office for MS Word and MS PowerPoint
Plugin to MS Office for Windows.
Creates tags according to the PDF/UA Standard.
Facilitates the tagging process.
CommonLook Dynamic
For Windows.
Creates tags according to the PDF/UA Standard.
Automatically tags and generates accessible PDF from
print streams and live data/databases.
Tools for creating accessible PDF according to the PDF/UA standard
"PDF/UA-Ready" software tools with the ability to create PDF documents
conforming to PDF/UA (ISO 14289-1:2014).
"PDF/UA-Ready" software tools for CREATING accessible PDF according to ISO PDF/UA:
axaio MadeToTag for Adobe InDesign
Plugin to Adobe InDesign. For Windows and macOS.
No need for revision / post-processing in Adobe Acrobat!
Creates PDF files compliant with ISO PDF/UA and PDF/A-2a.
axesWord for MS Word
Plugin to MS Word for Windows.
Creates PDF files compliant with ISO PDF/UA and PDF/A-2a.
CommonLook Office for MS Word and MS PowerPoint
Plugin to MS Office for Windows.
Creates PDF files compliant with
ISO PDF/UA, WCAG 2.0, U.S. Section 508 and/or U.S. HHS.
CommonLook PDF
Plugin to Adobe Acrobat for Windows.
Creates PDF files compliant with
ISO PDF/UA, WCAG 2.0/2.1, U.S. Section 508 and/or U.S. HHS.
CommonLook Dynamic
For Windows.
Automatically tags and generates accessible PDF from
print streams and live data/databases.
Creates PDF files compliant with
ISO PDF/UA, WCAG 2.0/2.1, U.S. 508 and/or U.S. HHS.
Tools for remediation/correction of inaccessible PDF
to accessible PDF according to the PDF/UA standard
"PDF/UA-Ready" software tools with the ability to remediate/correct
the logical structure tree of a tagged PDF file.
"PDF/UA-Ready" software tools for REMEDIATING/CORRECTING inaccessible PDF
to be in compliance with ISO PDF/UA, thus being accessible PDF:
axesPDF
Extended/professional version of PAC for Windows.
Corrects any existing PDF for compliance with ISO PDF/UA.
callas pdfaPilot
For Windows and macOS.
callas pdfaPilot can resolve some common problems related to PDF/UA files;
"Resolve structural problems with tagged PDF documents".
callas pdfToolbox
For Windows and macOS.
callas pdfToolbox can resolve some common problems related to PDF/UA files;
"Resolve structural problems with tagged PDF documents".
CommonLook PDF
Extended/professional version of CommonLook PDF Validator.
Plugin to Adobe Acrobat for Windows.
Corrects for compliance with
ISO PDF/UA, WCAG 2.0/2.1, U.S. Section 508 and/or U.S. HHS.
Tools for validation of PDF-files for
compliance with the PDF/UA standard
"PDF/UA-Ready" software tools with the ability to verify/confirm PDF/UA
conformance based on the Matterhorn Protocol's set of checks.
A PDF document’s degree of accessibility is hard to determine at first glance.
How, then, can you tell if and to what extent a PDF file meets
the requirements of PDF/UA?
A reliable compliance test always depends on at least two stages of validation:
- a programmatic syntactic test,
which can be performed by a trusted software, and
- an interactive semantic test,
manually carried out by a human.
Dedicated validation/accessibility checker/test tools help the user
to perform the programmatic syntactic test.
They test and show the extent to which the PDF document meets
the standard’s purely technical requirements (including requirements
for tag-based document structuring of document title, headings,
paragraphs, columns, tables, alternative text for images, etc...)
and uses the correct syntax to implement them.
For programmatic PDF/UA and WCAG compliance validation of a PDF document,
we recommend to validate the document with more than one test tool.
Note! Passing the programmatic syntactic test with an accessibility checker
is only the beginning of ensuring a document is accessible.
The semantic aspects of PDF/UA, however,
cannot be tested in the same way:
- Is the reading order logical?
- Does the alternative text adequately represent the same
information as the images to which it is attached?
- Do the header tags reflect their corresponding header levels?
These and other questions can only be answered after
evaluation and testing by a human user.
Both PDF/UA and WCAG always requires human interaction;
an interactive semantic test, manually carried out by a human.
One further test (which should be run on at least a random
sample of all documents created) is to use the PDF document
with a selection of current types of assistive technology.
Regular users of the technology can be enlisted to test
the documents in this way; in most cases, however,
anyone can in principle perform a useful test with assistive
technology to confirm the readability of the PDF document.
One very simple option here is to use the free
Windows screen reader program NVDA.
A user can quickly get to grips with the core functions of
the software in order to test how well people with disabilities can
actually use an existing (ideally fully PDF/UA-compliant) document.
"PDF/UA-Ready" software tools for VALIDATING
accessible PDF according to ISO PDF/UA:
PDF Accessibility Checker (PAC)
No cost. For Windows.
Quick check of a PDF file for compliance with ISO PDF/UA
and applicable parts of WCAG 2.1 AA recommendations.
Also performs automatic color contrast control.
axesCheck
No cost web-based service.
Web-based version of PDF Accessibility Checker (PAC).
Quick check of a PDF file for compliance with ISO PDF/UA
and applicable parts of WCAG 2.1 AA recommendations.
axesPDF
Extended/professional version of PAC for Windows.
Validates any existing PDF for compliance with ISO PDF/UA.
callas pdfaPilot
For Windows and macOS.
The feature for validation of PDF/UA compliance
can be used without cost without cost.
callas pdfToolbox
For Windows and macOS.
The feature for validation of PDF/UA compliance
can be used without cost without cost.
CommonLook PDF Validator
No cost plugin to Adobe Acrobat for Windows.
First fast way to validate a PDF file for compliance with
ISO PDF/UA, WCAG 2.0/2.1, U.S. Section 508 and/or U.S. HHS.
CommonLook PDF
Extended/professional version of CommonLook PDF Validator.
Plugin to Adobe Acrobat for Windows.
Validates for compliance with
ISO PDF/UA, WCAG 2.0/2.1, U.S. Section 508 and/or U.S. HHS.
CommonLook Clarity
For Windows.
Continually monitors websites, internal networks,
files systems and folders, and maps the status of accessible PDF.
Generates reports showing compliance with valid accessibility standards,
such as ISO PDF/UA, W3C/WCAG 2.0 AA, WCAG 2.1 AA,
U.S. Section 508 and U.S. HHS.
veraPDF
Open source project.
Validates for compliance with ISO PDF/UA (Machine Check).
Tools for quick viewing/reading of
the tagging structure in PDF files
"PDF/UA-Ready" software tools with the ability of product that includes
an end-user-oriented interactive PDF (or PDF-alternative) viewer that
uses tagged PDF to make PDF/UA files available to Assistive Technology.
"PDF/UA-Ready" software tools for VIEWING and READING
the tagging structure in PDF files, and assistive technologies
such as PDF reading tools and screen reading tools:
Tools for contrast checking
Adobe Contrast Checker
Free to use online-tool testing the contrast of your
background and text for visual accessibility.
Checks the contrast ratio of your background and text colors,
and compare to WCAG.
Adobe Color Blind Safe Checker
Free to use online-tool checking your color scheme and
simulating what the colors look like to color blind individuals,
warning you if colors are too close together.
WebAIM Contrast Checker
Free to use online-tool testing the contrast of your
background and text for accessibility.
You can use it to check if your website design
are in compliance with W3C/WCAG.
WCAG 2.0 level AA requires a contrast ratio of at least
4.5:1 for normal text and 3:1 for large text.
WCAG 2.1 requires a contrast ratio of at least 3:1 for
graphics and user interface components
(such as form input borders).
WCAG Level AAA requires a contrast ratio of at least
7:1 for normal text and 4.5:1 for large text.
Large text is defined as 14 point (typically 18.66px)
and bold or larger, or 18 point (typically 24px) or larger.
Monsido Online Color Contrast Checker
Free to use online-tool testing the contrast of your
background and text for accessibility.
You can use it to visualize different color combination palettes
for your website design that are in compliance with
W3C/WCAG, EU directive, and ADA standards.
TPGi Colour Contrast Analyser (CCA)
For Windows and macOS.
No cost Colour Contrast Analyser (CCA) from TPGi
that allows you to easily determine the contrast ratio of
two colors simply using an eyedrop tool.
Tools for mapping of existing business documents
for compliance with accessibility standards
"PDF/UA-Ready" software tools with the ability to continuously and
automatically monitor and map/report existing enterprise-wide
document resources and their accessibility status.
"PDF/UA-Ready" software tools for automatic mapping of
accessibility status for large volumes (bulks) of existing PDF files:
CommonLook Clarity
For Windows.
Continually monitors websites, internal networks, files systems and folders.
Automatically maps and validates all PDF documents with respect to
compliance with applicable accessibility standards.
Generates reports showing compliance with accessibility standards
such as ISO PDF/UA, W3C/WCAG 2.0 AA, WCAG 2.1 AA,
U.S. Section 508 and U.S. HHS.
Tools for businesses that need automated production of
large quantities of PDF/UA compliant files
"PDF/UA-Ready" software tools with the ability to continuously and
automatically produce large volumes of accessible PDF documents
from live data/databases.
"PDF/UA-Ready" software tools for automatic production of PDF/UA
compliant documents in large volumes from live data/databases.
CommonLook Dynamic
For Windows.
Automatically tags and generates accessible PDF from
print streams and live data/databases.
Creates PDF files compliant with accessibility standards
such as ISO PDF/UA, WCAG 2.0/2.1, U.S. 508 and/or U.S. HHS.
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