Google Summer of Code (GSoC)
253 organisations took part between 2024 and 2026. 200 have repositories measured so far, last updated 11 Oct 2026.
The ranking rule. Share of pull requests from outside the core team that got a reply from a person within 7 days, across all of the organisation's measured repositories. Ties go to the higher outside merge rate. An organisation needs at least 20 outside pull requests to take a place; smaller ones follow, unranked.
Each year Google funds new contributors to spend about 12 weeks building something for an open source project.
You work with a mentor from the organisation you applied to. You do not need to be a student, only new to open source and 18 or older.
You write a proposal to one of the organisations below. That is why it matters which of them reply to newcomers.
Details and dates are on the official Google Summer of Code site.
Now is the best time to start: contribute small fixes to the organisation you want, so the mentors know your name before applications open.
Oct
You are here.
Organisations
213 organisations measured on GitHub
Open-Source Tools for 3D Genomics Research
GSoC 2024 · 6 repositories measured
pythonnumpyscikit-learnpandashdf5
40 organisations cannot be measured on GitHub. They host their code elsewhere, or they are umbrella organisations whose projects change every year. They are listed so the ranking does not pretend they do not exist.
Mid January
Many publish their idea lists now.
Late February
Pick two or three and read their ideas.
Applications
Mid March
Send mentors a draft early for feedback.
End of March
About two weeks after opening.
End of April
Meet your mentor before coding starts.
Coding
Late May
About 12 paid weeks, midterm in July.
Late August
Larger projects can run into November.
Google has not published the 2027 dates yet; these follow the 2026 programme, which has kept the same shape for years. Official timeline
Empowering labs to Ensure Quality Health Care
GSoC 2024, 2025, 2026 · 0 repositories measured
postgresqljavascriptjavareactspring
Advancing Algorithms & AI for Biomedical Insights
GSoC 2026 · 0 repositories measured
pythoncythonc++pytorchstreamlit
Enhance people’s quality of life through Robotics
GSoC 2025 · 9 repositories measured
pythonjavascriptc++
Mesa: Agent-based modeling in Python 3+
GSoC 2024, 2025, 2026 · 0 repositories measured
pythongisobject oriented programmingllmsnetwork topology
Research on Multimodal Communication
GSoC 2024 · 0 repositories measured
pythonmachine learningnlpaidata science
A free rapid game development environment.
GSoC 2024 · 1 repository measured
openglc++qt5recursive-descent
Of course it runs NetBSD
GSoC 2024, 2025, 2026 · 3 repositories measured
cshell scriptmakeunixbsd
Dates for the next round are published by Google on the official timeline. Contributable is independent and not affiliated with Google.