The Berlin Declaration on Open Access to Knowledge in The Sciences and Humanities was published on 22 October 2003 and remains one of the most pivotal moments in the rise of the Open Access (OA) movement.

It affirmed the key technical requirements of an OA publication and called on institutions, policy makers, librarians, and funders to make the global knowledge freely and easily available online.

In this article, we look back at this historic declaration, exploring what it was, what caused it to happen, and how its legacy continues more than two decades later.

In need of an alternative

OA makes research openly available at no cost to the reader, facilitating the widespread dissemination of essential research and further scientific discovery. It began as a radical and bold idea which was brought about by the widespread public use of the internet in the 1990s.

As scholars became acquainted with the limitless potential that the internet provided for global communication and knowledge exchange, ideas about how this exciting technology could be applied to scholarly publishing began to form.

Journal subscription costs were also rising much faster than inflation and placed an immense financial burden onto the entire scholarly ecosystem. This was known as the serial crisis. Between 1986 and 2004, the consumer price index (CPI), which measures if the average price of goods or services are getting more or less expensive, increased by 73%. At the same time, research library expenditures for journal subscriptions increased by 273%.

The scholarly community needed an alternative, one that their institutions, libraries, and researchers could afford.

MDPI’s first journal, Molecules, was one of the first platforms to make scientific research outputs available to anybody who had access to the internet. However, the OA movement as we know it today was still to be fully realised and widespread adoption was yet to be seen.

Laying the foundations for change

The Berlin Declaration was not the first major documentation of OA ideas. In fact, two equally important declarations came just before it.

The term ‘Open Access’ was first coined during a meeting between scholars in Budapest, Hungary, in February 2002. This meeting became known as the Budapest Open Access Initiative (BOAI).

The Budapest Open Access Initiative (BOAI) was a wholly radical and aspirational declaration which set out to define exactly what OA publishing was and the core principles it championed. It discussed OA in broad terms but left key questions for future literature to address. Notably, the technical specifications of an OA publication.

Taking place in the following year (2003), the Bethesda Statement on Open Access Publishing set out to elaborate on what exactly qualifies as an OA publication. Here, scholars within the biomedical research community concluded that an OA publication must first permit “free, irrevocable, worldwide, perpetual right of access to… copy, use, distribute, transmit, and display the work publicly” and it must be immediately deposited in a publicly accessible repository.

Together, the Budapest and Bethesda meetings had taken OA from a mere idea to an established movement, supported with a clear purpose and a testable definition. Despite this, more refinement and advocacy were required before OA could become a global movement, especially given that its endorsement remained tied to independent proponents.

The Berlin Declaration on Open Access to Knowledge in The Sciences and Humanities

The Berlin Declaration originated from a conference hosted by the Max Planck Society and the European Cultural Heritage Online Project in Berlin, Germany.

As part of its preface, the declaration maintains that it is written “in accordance with the spirit of the Declaration of the Budapest Open Access Initiative, the ECHO Charter and the Bethesda Statement on Open Access Publishing”.

The Berlin Declaration, therefore, sought to build on, rather than deviate from existing ideas. It highlighted how the internet “has fundamentally changed the practical and economic realities of distributing scientific knowledge and cultural heritage” and elaborated on the specific measures which needed to be implemented.

Defining an OA contribution

When defining an OA publication, the Berlin Declaration aligned with what had been established previously. Like the Bethesda Statement had suggested earlier in the same year, it noted than an OA output must satisfy two conditions:

• Users must have “free, irrevocable, worldwide, right of access to” the works and be allowed to distribute derivative works.
• It must be immediately deposited in a publicly available repository.

Applying openness to the entire scientific process

However, the Berlin Declaration took this concept of openness even further. It extended these requirements to all components of the research process, including “raw data and metadata, source materials, digital representations of pictorial and graphical materials and scholarly multimedia material”.

Today, the increased accessibility of all scholarly materials is understood as the core ethos of the open science movement. Through this, we are reminded how truly pioneering this declaration was. It laid the foundations for future initiatives which argue that in order for science to be truly open, the principles of accessibility and transparency must be extended to all the components which inform scientific discovery.

Opening the humanities and culture heritage

While the Bethesda statement had proposed “significant, concrete steps” which should be taken to accelerate the transition to OA, it was exclusively attended by those in the biomedical research community and its language reflected that focus.

The Berlin Declaration broadened OA’s scope across all academic disciplines and envisaged the movement as “a comprehensive source of human knowledge and cultural heritage that has been approved by the scientific community”.

Rather than presenting OA as a solution for a single field’s challenge, the Berlin Declaration transformed OA into a universal principle for how knowledge should be shared. Now explicitly including “each and every individual producer of scientific knowledge and holder of cultural heritage”, it gave those working in the humanities stakes in a movement, until then, dominated by the sciences.

Institutional support

Another integral aspect of the Berlin Declaration is how it encouraged measurable institutional backing to OA.

Previous signatories of the BOAI and Bethesda statements signed as individuals. However, individuals alone were not enough to usher in sizeable change to scholarly publishing practices. So, while they were effective at demonstrating growing interest in making research widely available and easier to access, they alone couldn’t drive the adoption of OA on a larger scale.

The Berlin Declaration was signed by individuals on behalf of their institutions. This included various German research institutions and organisations, alongside other international bodies such as CNRS in France. By 2005, 55 institutions had signed the Declaration, including national scientific academies across countries such as China, India, and the Netherlands.

Berlin’s signatories sought to encourage the increased implementation of OA practices, which could only be brought around by those who influenced repositories, library budgets, and the production of scientific knowledge itself. In turn, the Berlin Declaration gave the movement the formal institutional mandate that it needed.

The Berlin Declaration, two decades later

The Berlin Declaration fortified the mission statement of Open Access (OA) and provided clear guidelines for institutions to adopt. Together with the Budapest Open Access Initiative (BOAI) and Bethesda Statement, it represents one of the key texts which makes up the ‘BBB’ definition of Open Access.

After its publication in 2003, the total number of institutions that have signed it has grown steadily. As of August 2026, 834 institutions across the globe have signed the declaration. The official list can be found here.

OA itself has evolved from a bold idea into the default expectation for a growing proportion of publicly funded research. With OA mandates becoming central to funder and institutional policy around the world, it is important to remember the Berlin Declaration as a key catalyst for this change.

Open Access is the new paradigm

MDPI has pioneered Open Access since for more than 30 years and defines Open Access in accordance with the definitions provided by the Budapest, Berlin, and Bethesda Declarations.

All research published across MDPI’s portfolio of more than 500 Open Access journals is immediately available online worldwide and may be reused without permission, provided that it is clearly cited.

We are dedicated to giving you all the information you need to understand Open Access. Our article All You Need to Know About Open Access covers a range of topics.