Open Source Startups funded by Y Combinator (YC) in the San Francisco Bay Area 2025

January 2025

Browse 32 of the top Open Source startups funded by Y Combinator. Headquartered in the San Francisco Bay Area, these are some of the hottest and fastest-growing startups.

We also have a Startup Directory where you can search through over 5,000 companies.

  • GitLab
    GitLab (w2015)Public • 2,000 employees • San Francisco, CA, USA
    GitLab is the first single application for the entire DevOps lifecycle. Only GitLab enables Concurrent DevOps, unlocking organizations from the constraints of today’s toolchain. GitLab provides unmatched visibility, radical new levels of efficiency and comprehensive governance to significantly compress the time between planning a change and monitoring its effect. This makes the software lifecycle 200% faster, radically improving the speed of business. GitLab and Concurrent DevOps collapses cycle times by driving higher efficiency across all stages of the software development lifecycle. For the first time, Product, Development, QA, Security, and Operations teams can work concurrently in a single application. There’s no need to integrate and synchronize tools, or waste time waiting for handoffs. Everyone contributes to a single conversation, instead of managing multiple threads across disparate tools. And only GitLab gives teams complete visibility across the lifecycle with a single, trusted source of data to simplify troubleshooting and drive accountability. All activity is governed by consistent controls, making security and compliance first-class citizens instead of an afterthought. Built on Open Source, GitLab leverages the community contributions of thousands of developers and millions of users to continuously deliver new DevOps innovations. More than 100,000 organizations from startups to global enterprise organizations, including Ticketmaster, Jaguar Land Rover, NASDAQ, Dish Network and Comcast trust GitLab to deliver great software at new speeds.
    developer-tools
    devsecops
    open-source
  • CoreOS
    CoreOS (s2013)Acquired • 150 employees • San Francisco, CA, USA
    CoreOS is part of the Red Hat family. A leader in the open source community and an innovator of open source projects, CoreOS creates and delivers critical components for containerized applications that help fuel broad adoption of secure, scalable and resilient infrastructure. The team maintains several open source projects, including: Container Linux: the secure automatic updating OS; and etcd, the distributed data store for Kubernetes. Join us at https://coreos.com/ and @CoreOS on Twitter.
    open-source
    devops
  • Protocol Labs
    Protocol Labs (s2014)Active • 130 employees • Palo Alto, CA, USA
    Protocol Labs is an open-source research, development, and deployment laboratory. Our projects include IPFS, Filecoin, libp2p, and many more. We aim to make human existence orders of magnitude better through technology. Some of our projects. IPFS makes the web work peer-to-peer. IPFS is a protocol for storing, addressing, and transferring data, designed to replace HTTP in many contexts. IPFS uses content-addressing to uniquely identify and link to information. IPFS is one of the leading protocols of Web3, crypto, and the decentralized web movements. IPFS serves millions of end users and tens of thousands of developers. It powers the websites and applications of small startups, large enterprises, and even blockchains. Filecoin is a decentralized storage network, designed to store humanity's most important information. Filecoin is a cryptocurrency incentivized decentralized market, where storage providers earn filecoin tokens for renting out storage space. (Think airbnb for cloud storage). Filecoin is one of the leading projects in the cryptocurrency/blockchain space.
    crypto-web3
    open-source
  • Firezone
    Firezone (w2022)Active • 6 employees • Mountain View, CA, USA
    Firezone connects your workforce to the computing resources they need, wherever they are, securely. Unlike traditional VPNs, Firezone uses a least-privileged approach to access control known as Zero Trust Access. Connect your identity provider and define granular policies in minutes, then rejoice in the IT support requests you won't receive due to our lightweight, WireGuard-powered clients which work great on all platforms.
    devsecops
    next-gen-network-security
    b2b
    security
    open-source
  • Airbyte
    Airbyte (w2020)Active • 90 employees • San Francisco, CA, USA
    Airbyte is the leading open data movement platform that empowers data teams in the AI era by transforming raw data into actionable intelligence. With the largest catalog of over 350 connectors, it offers low-code, no-code, and AI-powered connector development, and provides flexible deployment options across self-hosted, cloud, and hybrid environments. https://github.com/airbytehq/airbyte
    developer-tools
    open-source
    data-engineering
  • PostHog
    PostHog (w2020)Active • 55 employees • San Francisco, CA, USA
    PostHog helps engineers build better products. We provide everything they need to make sure they are building something that people want. This means - product analytics, session replays, feedback tools, feature flags, experimentation, and a datawarehouse (with SQL) with one click data imports from the places you use. PostHog can be deployed to the cloud, or self-hosted on existing infrastructure, removing the need to send data externally. PostHog was created as an open source project during Y Combinator's W20 cohort and had the most successful B2B software launch on HackerNews since 2012 - with a product that was just 4 weeks old. Since then, more than 40,000 companies have installed the platform, we're doing $MMs in revenue, and have a community of 120K developers - 97% driven by word of mouth. Despite the tech market, we're default alive and doing better than ever! We've been averaging ~10% monthly revenue growth, we are [default alive](http://www.paulgraham.com/aord.html), and we didn't raised a huge / now-overpriced round in 2021. While others are focused on layoffs and struggling to grow into huge valuations, we're focusing on an awesome product for end users, hiring (a handful of) exceptional team members and seeing fantastic increases in revenue as a result. Check out posthog.com/careers if you want to be part of this journey.
    b2b
    open-source
  • Replicate
    Replicate (w2020)Active • 27 employees • San Francisco, CA, USA
    artificial-intelligence
    developer-tools
    machine-learning
    community
    open-source
  • Jitsu
    Jitsu (s2020)Active • 4 employees • San Francisco, CA, USA
    Jitsu is the fastest, most durable way to collect event data from every source - web, app, email, chatbot, CRM - into your data warehouse. 100% open-source. Purpose built, secure and ready in minutes.
    saas
    b2b
    open-source
    data-engineering
  • InfluxData
    InfluxData (w2013)Active • 210 employees • San Francisco, CA, USA
    InfluxData, the creators of InfluxDB, delivers a modern Open Source Platform built from the ground up for analyzing metrics and events (time series data) for DevOps and IoT applications. Whether the data comes from humans, sensors, or machines, InfluxData empowers developers to build next-generation monitoring, analytics, and IoT applications faster, easier, and to scale delivering real business value quickly. Based in San Francisco, InfluxData customers include Autodesk, Cisco, eBay, and Coupa. Visit https://www.influxdata.com.
    analytics
    open-source
    time-series
    databases
  • Activeloop
    Activeloop (s2018)Active • 15 employees • Mountain View, CA, USA
    We provide a simple API for creating, storing, versioning, and collaborating on multi-modal AI datasets of any size. With Activeloop's open-core stack, you can rapidly transform and stream data while training models at scale. Deep Lake powers foundational model training by acting as a vector database with significant benefits, such as (1) the ability to use multi-modal datasets to fine-tune your own LLM models, (2) storing both the embeddings and the original data with automatic version control, so no embedding re-computation is needed (3) truly serverless service with no vendor lock-in. How cool is that? GitHub loves us - we're one of the fastest-growing libraries there, and we're used by little-known companies like Google, Waymo, and Intel. No big deal. Our founding team hails from places like Princeton, Stanford, Google, and Tesla, and we're backed by Y Combinator & other Silicon Valley heavyweights. Activeloop is hiring, and we want you! Check out our open roles on our YC page and join the fun. 10-min demo: https://activeloop.wistia.com/medias/aibvo0dst2 Whitepaper: https://www.deeplake.ai/whitepaper
    computational-storage
    deep-learning
    generative-ai
    computer-vision
    open-source
  • Okteto
    Okteto (w2019)Active • 30 employees • San Francisco, CA, USA
    At Okteto, we are working hard at creating the next-generation development experience for teams of all sizes. Have you ever seen how long it takes a developer to set up everything they need before working on a feature? We are fixing that. We want developers to focus on building value for their teams instead of wasting time setting up local environments or trying to debug "production only" issues.
    developer-tools
    saas
    b2b
    open-source
    kubernetes
  • Medplum
    Medplum (s2022)Active • 3 employees • San Francisco, CA, USA
    Medplum makes it easy to build healthcare webapps that are compliant and interoperability ready. Our open source toolkit allows healthcare providers write apps that are HIPAA compliant, SOC2 certified and FHIR native - streamlining payor connections, health system integrations and more.
    developer-tools
    open-source
    healthcare
  • Mattermost
    Mattermost (s2012)Active • 120 employees • Palo Alto, CA, USA
    Mattermost provides secure collaboration for technical and operational teams that work in environments with complex nation-state level security and trust requirements. We serve technology, public sector, national defense and financial services industries with customers ranging from tech giants, to the world’s largest banks, to the U.S. Department of Defense and governmental agencies around the world. Our self-hosted and cloud offerings provide team messaging, file sharing, integrations, audio and screen share, workflow automation and project management on an open source platform deployed by the world’s most secure and mission critical organizations. We co-build the future of collaboration with over 4,000 open source project contributors who’ve provided over 30,000 code improvements towards our shared product vision, which is translated into 20 languages.
    devsecops
    collaboration
    security
    open-source
  • Apollo
    Apollo (s2011)Active • 200 employees • San Francisco, CA, USA
    Apollo GraphQL is the leader in open source and commercial GraphQL technologies. Apollo’s open-source GraphQL client, server, and gateway are downloaded more than 17M times per month and used in production by over 30% of the Fortune 500. Customers like Walmart, Expedia, Glassdoor, Audi, and PayPal, use the Apollo Graph Platform to unify their GraphQL efforts, collaborate on graph development, and safely iterate on their graphs. Based in San Francisco, Apollo is backed by Insight Partners, Andreessen Horowitz, Matrix Partners, Trinity Ventures, Y Combinator and individual investors.
    developer-tools
    open-source
    graphql
  • Daily
    Daily (w2016)Active • 62 employees • San Francisco, CA, USA
    Daily is real-time voice, video, and AI for developers. Our cross-platform SDKs and global infrastructure enable ultra-low latency, highest quality experiences for developers building real-time voice and video AI agents. Our platform also supports integration of traditional voice/video calls, in addition to AI agent experiences.
    developer-tools
    open-source
    ai
    ai-assistant
  • MindsDB
    MindsDB (w2020)Active • 33 employees • San Francisco, CA, USA
    MindsDB is a fast-growing AI startup headquartered in San Francisco, California. As a leading innovator bringing AI and Data together, our passion is empowering companies to easily build AI capabilities that can Think, Understand and Orchestrate: enabling teams to move from prototyping & experimentation to production in a fast & scalable way. MindsDB was founded in 2017 by Adam Carrigan and Jorge Torres, inspired by Ian M. Banks's Culture series, in which super AI systems called Minds collaborate with other forms of life to accomplish incredible goals. Starting as an Open-Source project, MindsDB has grown to be one of the most widely used AI-Data platforms in the world, with a growing community and more than 700 contributor developers from every corner of the globe. We are backed with over $55M in funding from Mayfield, Benchmark, YCombinator, and nVidia. MindsDB is also recognized by Forbes as one of America's most promising AI companies (2021) and by Gartner as a Cool Vendor for Data and AI (2022).
    artificial-intelligence
    developer-tools
    machine-learning
    open-source
    enterprise-software
  • SuperTokens
    SuperTokens (s2020)Active • 10 employees • San Francisco, CA, USA
    SuperTokens is building open source authentication (as an alternative to Auth0, Firebase and AWS Cognito). Add secure, hassle free authentication to your app in 1 day. We enable startups to launch quicker and focus on their core product offering 1. We're easier to implement as we take a modular approach - making it possible to pick only the features you need for your use case. This means you need not worry about complications associated with other features (eg: SSO and OAuth if you don’t need it) and this in turn makes it easier to implement and manage SuperTokens. 2. Developer's can own and manage their user's data. 3. SuperTokens can be run on your premise for free and also has a generous hosted tier for those who dont want to manage it themselves. SuperTokens is being used by hundreds of developers across the globe.
    developer-tools
    saas
    b2b
    open-source
  • Docker
    Docker (s2010)Active • 201 employees • San Francisco, CA, USA
    Docker is the world’s leading software container platform. Developers use Docker to eliminate “works on my machine” problems when collaborating on code with co-workers. Operators use Docker to run and manage apps side-by-side in isolated containers to get better compute density. Enterprises use Docker to build agile software delivery pipelines to ship new features faster, more securely and with confidence for both Linux and Windows Server apps.
    open-source
    devops
    enterprise-software
  • Laudspeaker
    Laudspeaker (w2021)Active • 3 employees • Mountain View, CA, USA
    Open source mobile marketing automation and customer onboarding platform. Alternative to braze customer io / iterable / pendo / appcues . Segment and engage your users with complex scheduled push notification, sms and email campaigns.
    saas
    b2b
    open-source
    automation
  • Chaos Genius
    Chaos Genius (w2020)Active • 10 employees • San Francisco, CA, USA
    Chaos Genius is a DataOps Observability platform for Snowflake. Enable Snowflake Observability to reduce Snowflake costs and optimize query performance.
    cloud-workload-protection
    machine-learning
    analytics
    open-source
    data-engineering
  • Chatwoot
    Chatwoot (w2021)Active • 8 employees • San Francisco, CA, USA
    Chatwoot is an open-source omnichannel customer engagement suite built as an alternative to Intercom, Zendesk etc. Chatwoot helps you to connect email, website live chat, social media handles, WhatsApp etc. and manage all your customer interactions from one place.
    b2b
    customer-success
    open-source
    customer-service
    customer-support
  • Wasmer
    Wasmer (s2019)Active • 11 employees • San Francisco, CA, USA
    We are working on the software that will power the next generation of Cloud Computing (Edge Computing) platforms using WebAssembly. You can see us as a mix between Docker (but 100x more performant in startup time, and with 100x more lightweight containers), npm (we released the first WebAssembly package manager: wapm.io) and the JVM (but more universal).
    developer-tools
    open-source
  • Evidently AI
    Evidently AI (s2021)Active • 2 employees • San Francisco, CA, USA
    We are building an open-source standard to monitor ML models in production. The tool is used by enterprise data science teams to operate their models reliably and detect and resolve issues.
    developer-tools
    machine-learning
    b2b
    open-source
  • GrowthBook
    GrowthBook (w2022)Active • 21 employees • Palo Alto, CA, USA
    GrowthBook is an open source platform to help companies make data-driven product decisions with feature flags and A/B tests. Existing SaaS solutions like LaunchDarkly require a company to send all of their data to them. This results in high costs, data compliance issues, and vendor lock-in. As a result, many companies end up building their own platforms in-house, which can take thousands of hours of work and lots of headaches. To solve this, GrowthBook uses a company's existing data infrastructure and business metrics. We believe feature flags and experimentation are the right way to build products at scale and that they will become a standard part of the development process. GrowthBook is well positioned to be a leader in this growing market.
    developer-tools
    b2b
    analytics
    open-source
  • BotCity
    BotCity (w2022)Active • 18 employees • San Francisco, CA, USA
    The rise of Robotic Process Automation offered a promise that any business user can build automations. We were skeptical about that and decided to talk to users of platforms such as UiPath, Automation Anywhere, and Blueprism, all of them low-code. Talking to users, we discovered that unique automations incorporating exclusive company processes and intelligence that have the potential to transform the business must be implemented by tech teams. It's not about mimicking employees performing isolated tasks. It's about designing a new workflow, integrated with the company's technological stack and systems. There are just 100.000 RPA skilled users compared to 22M developers globally that can become RPA coders on Day 1 with BotCity. We believe that all automation efforts in a single platform is more efficient. We started delivering the best RPA experience for tech teams, but we envision creating the perfect place to also manage crawlers, integrations, scrappers, data operations. Every company automation in a single place. As companies are becoming tech first and automation will be a basic KPI, we are building to be the all-in-one automation ops management.
    developer-tools
    robotic-process-automation
    computer-vision
    open-source
    ai
  • Grai
    Grai (s2022)Active • 3 employees • San Francisco, CA, USA
    Grai is open source version control for metadata. We can determine how database changes will affect deployed machine learning models, apis, and dashboards because we understand how data relates across systems which don’t otherwise talk to each other.
    developer-tools
    saas
    analytics
    open-source
    data-engineering
  • Citus Data
    Citus Data (s2011)Acquired • 45 employees • San Francisco, CA, USA
    The amount of time businesses spend on their databases is altogether too much time. Citus is fixing this problem. Citus is worry-free Postgres. Built to scale out, Citus is an extension to Postgres that is available as open source, as enterprise software that can be run on-prem or on any cloud, and as a fully-managed database as a service. Whether you have a multi-tenant application that needs to scale out, or you need performance for your real-time analytics customers, with Citus, you can focus on your app—not your database. Founded in 2011, Citus Data is venture backed by Khosla Ventures and Data Collective. Citus is a Y Combinator alumnus and has offices in San Francisco’s SoMa district and Istanbul, Turkey. At Citus, we make it simple to scale out Postgres. Citus Data online: www.citusdata.com Documentation: docs.citusdata.com GitHub: github.com/citusdata/citus
    open-source
    big-data
    databases
  • RethinkDB (s2009)Acquired • 11 employees • San Francisco, CA, USA
    RethinkDB is the first open-source scalable database for the realtime web. It exposes an exciting new access model -- instead of polling for changes, the developer can tell the database to continuously push updated query results to applications in realtime. RethinkDB allows developer to build scalable realtime apps in a fraction of the time with fewer engineering resources. RethinkDB features a pleasant and powerful query language that has useful queries like table joins and groupBy, a highly parallelized architecture, and web tools for managing clusters.
    open-source
  • Pyroscope
    Pyroscope (w2021)Acquired • 5 employees • Oakland, CA, USA
    Pyroscope is an open source continuous profiling platform. With just a few lines of code it will help you debug performance issues and find bottlenecks in your code.
    developer-tools
    saas
    open-source
    kubernetes
  • Fig
    Fig (s2020)Acquired • 5 employees • San Francisco, CA, USA
    Fig is re-imagining the terminal. We make it more accessible to beginners and more productive for advanced engineers Our first product is autocomplete, but we plan to expand into a full App Store ecosystem for the Terminal. We can do a bunch of cool stuff, check out our website. And if you're interested, we are hiring 😀
    developer-tools
    devsecops
    open-source