PDF Differences – one year later
Repeatable, reliable rendering and functionality are at the very heart of PDF’s value to users.
The synthetic targeted test files provided by the PDF Association in the public pdf-differences GitHub repository are specifically designed to make the changes in the latest PDF specification, ISO 32000-2:2020 as visually understandable as possible. Each case is built around a past issue discussed by PDF experts at the PDF Association or ISO tables and resulted in corrections or clarifications to the PDF specification (ISO 32000-2:2020 including errata set 2).
In late 2023 the PDF Association publicly released the first set of cases. While many cases relate to page rendering, some relate to other important end-user functionality such as support for page labels (see this article) and testing for unknown filters (especially important in preparation for future PDF changes, see this article).
Although some implementations have made corrections in the past 12 months, it is clear that many have not – as a result, many implementations continue to fail to support PDF correctly leading to visual differences between implementations which can be extremely confusing and frustrating for users.
Supporting publications and test suites
We’ve established a new public GitHub repository to allow anyone to log and discuss issues and requests against PDF Association publications.
