Portal of Croatian Scientific and Professional Journals HRČAK is a national portal that enables editorial teams to publish their journals in open access, while also providing users with a single point of access to Croatian open access journals. The portal is developed and maintained by the University of Zagreb University Computing Centre SRCE, which is responsible for the development, maintenance, and hosting of the platform, as well as providing technical infrastructure, user support, and ensuring interoperability and long-term accessibility. By aggregating a large number of scientific and professional publications in one place, HRČAK significantly increases the visibility, accessibility, and impact of Croatian scholarly output. The portal was launched in 2006, and, in its early years, the evaluation of journals relied on the expert team that originally designed and maintained the platform.

Over time, with the growth of the portal and the increasing number of journals, the need for a more transparent and structured evaluation framework became evident. Consequently, in 2017 a set of criteria for including journals in HRČAK was defined for the first time. These criteria primarily focused on assessing the quality of editorial processes, including the transparency of editorial policies, peer review procedures, publication ethics, and the availability of key information such as licensing and authorship.

Journals undergo an evaluation procedure upon inclusion in HRČAK. However, once accepted, no systematic re-evaluation process had been in place, which created a gap in ensuring the long-term maintenance of quality standards. During preparations for the Diamond Discovery Hub evaluation in 2024–2025, the idea emerged to introduce a re-evaluation of journals in HRČAK through a certification process. The aim was to ensure continued compliance with established quality standards, as well as to encourage journals to further develop and improve their editorial practices in line with evolving expectations in open access publishing.

The concept of certification was presented at several conferences and professional meetings, where it was discussed with journal editors. Feedback was also collected from the HRČAK Advisory Board, which played an important role in refining the criteria and the overall approach. This collaborative process contributed to the development of a model that balances quality assurance with the diversity of editorial practices across different disciplines.

During the first half of 2026, the first cycle of journal certification was carried out on the HRČAK. The certification process aimed not only to evaluate compliance with existing criteria, but also to recognise and promote journals that demonstrate a particularly high level of editorial quality and transparency. In the first round, two certification labels were awarded: “HRČAK Certified” and “Diamond Journal”.

The presentation provides an overview of the certification results, the challenges encountered during the process, key conclusions, and future directions for improving journal quality in accordance with HRČAK’s evaluation criteria and established editorial standards.