Aiming to spot some Open Access trends in scholarly publishing 2015–2024, on May 13, I retrieved publication volume data—specifically article-level outputs, excluding other document types—from OpenAlex, focusing on Open Access (OA) publishing trends and their respective modalities. Here, I share a brief overview of the results.
Total number of published articles and Open Access shares
From 2015 to 2023, the share of OA publications steadily increased from 22% to a peak of 59%. This upward trajectory underscores the growing normalization of open dissemination practices in scholarly communication. The year 2024, however, marks a noticeable departure: the OA share dropped to 47%, despite a stable overall output volume.
| Year | All Articles (closed and open) | Open Access | % OA |
|---|---|---|---|
| 2015 | 7.200.182 | 1.605.639 | 22% |
| 2016 | 7.234.861 | 1.796.599 | 25% |
| 2017 | 6.818.531 | 2.033.687 | 30% |
| 2018 | 6.784.177 | 2.294.978 | 34% |
| 2019 | 7.031.414 | 2.573.663 | 37% |
| 2020 | 7.144.144 | 2.965.644 | 42% |
| 2021 | 6.558.639 | 3.225.595 | 49% |
| 2022 | 5.716.901 | 3.393.457 | 59% |
| 2023 | 5.988.060 | 3.561.878 | 59% |
| 2024 | 6.200.186 | 2.911.329 | 47% |
Among the various OA routes, Gold OA—direct publication in Open Access journals—remained the most dominant model, expanding from roughly 470,000 articles in 2015 to over 1.43 million in 2023. Hybrid OA (and to a limited extent Diamond OA) models also gained ground, the latter being particularly notable for its no-cost model for both authors and readers.
Shares of Open Access types among all (closed and Open Access) publications
While the share of Gold OA within total Open Access output increased by 14 percentage points between 2015 and 2024, the share of Hybrid OA rose by 8 percentage points over the same period. Bronze OA saw a 5-point increase between 2015 and 2023, but returned to its 2015 baseline in 2024. The proportion of Green OA remained relatively stable throughout the years, yet dropped below the 2015 level in 2024—a decline likely attributable to the common practice of delayed Open Access following embargo periods, suggesting a temporal lag in the data. Diamond OA grew by 3 percentage points from 2015 to 2024.
| Year | All Articles (closed and open) | Open Access | % OA | Gold | % Gold | Hybrid | % Hybrid | Bronze | % Bronze | Green | % Green | Diamond | % Diamond |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2015 | 7.200.182 | 1.605.639 | 22% | 469.785 | 7% | 197.868 | 3% | 466.951 | 6% | 281.820 | 4% | 189.215 | 3% |
| 2016 | 7.234.861 | 1.796.599 | 25% | 557.612 | 8% | 214.802 | 3% | 484.573 | 7% | 310.242 | 4% | 229.370 | 3% |
| 2017 | 6.818.531 | 2.033.687 | 30% | 702.565 | 10% | 231.090 | 3% | 514.777 | 8% | 319.494 | 5% | 265.761 | 4% |
| 2018 | 6.784.177 | 2.294.978 | 34% | 875.884 | 13% | 255.393 | 4% | 535.977 | 8% | 327.405 | 5% | 300.319 | 4% |
| 2019 | 7.031.414 | 2.573.663 | 37% | 1.135.782 | 16% | 258.735 | 4% | 541.192 | 8% | 326.319 | 5% | 311.635 | 4% |
| 2020 | 7.144.144 | 2.965.644 | 42% | 1.336.558 | 19% | 353.990 | 5% | 563.096 | 8% | 363.347 | 5% | 348.653 | 5% |
| 2021 | 6.558.639 | 3.225.595 | 49% | 1.434.708 | 22% | 467.085 | 7% | 565.275 | 9% | 377.780 | 6% | 380.747 | 6% |
| 2022 | 5.716.901 | 3.393.457 | 59% | 1.452.620 | 25% | 601.274 | 11% | 584.705 | 10% | 388.292 | 7% | 366.566 | 6% |
| 2023 | 5.988.060 | 3.561.878 | 59% | 1.432.676 | 24% | 791.915 | 13% | 648.024 | 11% | 297.866 | 5% | 391.395 | 7% |
| 2024 | 6.200.186 | 2.911.329 | 47% | 1.308.519 | 21% | 705.163 | 11% | 378.325 | 6% | 134.560 | 2% | 384.762 | 6% |
Shares of Open Access types among all Open Access publications
The shifts among the various Open Access models become more apparent when examining their internal distribution within the total Open Access output.
| Year | OA Articles | Gold | % Gold | Hybrid | % Hybrid | Bronze | % Bronze | Green | % Green | Diamond | % Diamond |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2015 | 1.605.639 | 469.785 | 29% | 197.868 | 12% | 466.951 | 29% | 281.820 | 18% | 189.215 | 12% |
| 2016 | 1.796.599 | 557.612 | 31% | 214.802 | 12% | 484.573 | 27% | 310.242 | 17% | 229.370 | 13% |
| 2017 | 2.033.687 | 702.565 | 35% | 231.090 | 11% | 514.777 | 25% | 319.494 | 16% | 265.761 | 13% |
| 2018 | 2.294.978 | 875.884 | 38% | 255.393 | 11% | 535.977 | 23% | 327.405 | 14% | 300.319 | 13% |
| 2019 | 2.573.663 | 1.135.782 | 44% | 258.735 | 10% | 541.192 | 21% | 326.319 | 13% | 311.635 | 12% |
| 2020 | 2.965.644 | 1.336.558 | 45% | 353.990 | 12% | 563.096 | 19% | 363.347 | 12% | 348.653 | 12% |
| 2021 | 3.225.595 | 1.434.708 | 44% | 467.085 | 14% | 565.275 | 18% | 377.780 | 12% | 380.747 | 12% |
| 2022 | 3.393.457 | 1.452.620 | 43% | 601.274 | 18% | 584.705 | 17% | 388.292 | 11% | 366.566 | 11% |
| 2023 | 3.561.878 | 1.432.676 | 40% | 791.915 | 22% | 648.024 | 18% | 297.866 | 8% | 391.395 | 11% |
| 2024 | 2.911.329 | 1.308.519 | 45% | 705.163 | 24% | 378.325 | 13% | 134.560 | 5% | 384.762 | 13% |
The Gold OA share among all articles published Open Access grew from 29% in 2015 to 45% in 2024—a 16 percentage point increase. It has become the dominant model, likely driven by APC-based business models, funder mandates, and initiatives such as Plan S. Hybrid OA increased from 12% (2015) to 24% (2024) with the strongest increase between 2021 and 2024. It is still gaining ground, particularly through transformative agreements. Bronze OA declined steadily from 29% (2015) to 13% (2024). It seems to have lost traction, likely due to its unclear licensing and limited reusability. Green OA dropped from 18% (2015) to just 8% in 2023 or 11% in 2022 (I ignore the 5% rate in 2024 due to the delay in publishing Green due to embargo constraints). Diamond OA shows a very slight increase from 12% (2015) to 13% (2024) — it appears more stable than Bronze or Green Open Access, but remains far from displacing Gold or Hybrid Open Access.
In a nutshell
- Open Access has claimed an increasingly large share of total article output, peaking at 59% in 2023. However, this was followed by a notable drop to 47% in 2024, which may in part reflect shifts in publishing policies by controversial Open Access publishers in response to growing criticism.
- Gold and Hybrid OA continue to expand and shape the Open Access landscape.
- Bronze and Green OA are declining in visibility, with Green OA particularly affected by delayed availability.
- Diamond OA remains stable and is recognized as a promising equitable publishing model, but so far does not really challenge Gold and Hybrid OA.
The data retrieved from OpenAlex is available as:
Herb, U. (2025). Open Access Publishing Patterns 2015–2024: Global Article Output and Modal Shifts [Data set]. Zenodo. https://doi.org/10.5281/zenodo.15423474