Frequently asked questions (FAQ)

What does PAC cost?

PAC is completely free of charge for all types of applications.

Does PAC access the internet?

No, PAC does not access the Internet in any way.

Do the AI tests in PAC access the internet?

No. The AI model that is deployed with PAC runs entirely locally.

Here you will find more answers to frequently asked questions about AI-assisted checks.

Will my documents be used to train the AI? 

No. The AI runs entirely locally. Your documents are not sent to the internet and are therefore not used to train an AI.

Here you will find more answers to frequently asked questions about AI-assisted checks.

Is PAC also approved for commercial applications and free of charge?

Yes, as long as you comply with point 7.2 of our General Terms.

Is there a Mac version of PAC?

There is currently no Mac version, but one is in development. An initial prototype version will be presented at axes4 Day in March 2026, one of the most important trade events for document accessibility.

Can I use PAC via command line in batch processes?

No. We provide axesSense for this purpose. axesSense is available as a web service or as a local installation.

Does PAC run under Citrix, Terminal Server and similar systems?

Yes.

How can I roll out PAC to many people?

To do this, use the MSI file provided on the download page.
Rollout within your organization is possible, but subject to approval by axes4. Please note section 7.2 of our General Terms.

The PDF/UA and WCAG checks show green checkmarks, but the quality checks do not ‒ is this relevant for me?

See our explanations on the quality checks and the AI-assisted checks.

Is there a penetration test or software security check for PAC?

Penetration testing is relevant for software that interacts with external systems, such as Web applications, networked desktop applications, APIs, or cloud services.

PAC is a standalone Windows desktop application with no internet or network connectivity. It runs in isolation, doesn't expose APIs or services and has no inter-process communication.

Nevertheless, we have considered the following types of risk after a security analysis: 

  • Could a malicious local user exploit the app?

No, because PAC does not access any sensitive internals of the system.

  • Are there hardcoded secrets, unencrypted sensitive data, or privilege escalation risks?

No.

  • Are there buffer overflows, memory corruption, or insecure data handling? Are DLLs loaded securely?

No. PAC runs on .NET which avoids such issues by design.

  • Is there a risk of license bypassing, tampering, or code injection?

No. There is no licensing system. PAC is digitally signed; any tampering and code injection would result in the removal of this signature that you can check yourself in the file properties of PAC.exe.

  • Does your app store sensitive data unencrypted on disk?

No.

With this in mind, we don't provide external security checks like SOC 2, HECVAT, SSAE 18 etc. This would mean a lot of unnecessary effort and costs for a product that we would like to continue to offer free of charge.

Is the test result legally compliant and does it guarantee absolute accessibility?

The PDF Accessibility Checker PAC is the globally used tool for checking accessible PDF files and has been established since 2010. It supports both the DIN/ISO standard PDF/UA and the WCAG (Web Content Accessibility Guidelines). Not all requirements of both standards and guidelines can be checked automatically by software. Additional checks by a human are always required, for example to determine whether the semantic markup is appropriate. The test result can therefore not be legally binding, but it is an indicator. If all the check marks are green on the PDF/UA and WCAG tabs, this only means that all automatically checkable requirements have been met.