175 YC Open Source Startups
175 Y Combinator companies carry the Open Source tag in YC's own directory, across every batch since 2005. Each row shows what the company does, its batch, HQ and status, and links to its YC application reconstructed in the real form, so a founder building a Open Source startup can read how accepted companies answered the same questions.
- Companies
- 175
- Top industries
- B2B, Consumer and Healthcare
- Top locations
- San Francisco, New York and London
- YC top companies
- 2
Read the YC application of all 175 companies
- Every company's YC application, reconstructed in the real form
- Filter every batch by industry, country and team size
- Then find the investors who fund startups like yours
The first 100 companies, top companies first
That is 10 of 175.
Every company below has its YC application reconstructed in YC Insights. Create a free account to read them all.
The other 75 companies
Every remaining company in this list, A to Z. Each link opens the company's public page.
Applying to YC? Study these applications first.
YC Insights holds the reconstructed application of every company on this page, filterable by batch, industry and country, next to 60,000+ investors who fund startups like yours.
About this list
This list is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise. How this data is built.
Frequently Asked Questions
How many Y Combinator companies are in tagged Open Source?
This directory lists 175 YC companies in tagged Open Source, out of 6,207 across every batch since 2005. The count updates when the directory is refreshed, and every one of them is on this page with a link to its public profile.
Are the YC applications on these pages real?
No. YC keeps submitted applications private. Every application linked from this list is a reconstruction: the real YC form questions, answered from the company's public data. The Company section is free on each page; the rest opens in YC Insights.
Which companies on this page are best known?
CoreOS and GitLab lead the table above. YC marks 2 of the 175 companies here as top companies, its own list of the highest-valued and highest-revenue alumni.
How do I use this list when applying to YC?
Pick five companies on this page whose product is closest to yours, read their reconstructed applications side by side in YC Insights, and note how each answers the same question. Then write your own answers to that standard.
Where does this data come from?
From YC's public company directory, refreshed by batch, with each company's status, industry and location as YC reports them. Round Funded adds the reconstructed application and the founder profiles; nothing private is published.
What is Round Funded?
Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.