In 2025, we're celebrating 20 years of Symfony. Over these years, thousands of people have contributed code to Symfony. Some folks fixed a small typo in a comment, while others added more than 100,000 lines of code. All contributions are welcome and essential in a project as large and impactful as Symfony.
Wouter de Jong, a Symfony Core Team member and one of the top contributors to the Symfony Docs, has published a blog post packed with statistics about the Symfony codebase, including many charts that make it easy to explore data such as:
- Merged pull requests by type (feature, bug, minor) per year
- First-time commit authors over time
- Breakdown of authors by number of lines contributed
- Cyclomatic complexity metrics (average, p99, worst case)
- And much more
Here's an example of one of the interesting stats included in the blog post:
This chart shows how many lines of code written in a given year are still
present and unchanged in the latest Symfony releases. For example, when
Symfony 2.0 was released in 2011, around 70% of its code was written that
same year. In Symfony 8.0, around 11% of the code was written in 2025.
Interestingly, 2019 is the year that contributed the largest amount of code
still in use today. This is mainly because that year marked the transition
from the legacy array() syntax to the short array syntax [].