Jitsu collects event data from sites, apps and servers and routes it in real time to warehouses and tools like PostHog, GA4 and Meta — an open-source Segment.
Yes, Jitsu is open source under the MIT license.
Jitsu is free to use.
Yes, Jitsu can be self-hosted (the source is available under the MIT license).
Jitsu is an open-source alternative to Segment: it collects event data from websites, apps, and servers and routes it in real time to data warehouses and third-party tools such as PostHog, GA4, Meta, and ad platforms. Open source: yes (MIT); fully self-hostable with no feature gating, and there is a managed option at jitsu.com. It is free (open-core), has ~5.1k stars, and is maintained by jitsucom.
Jitsu is an event-data pipeline. It ingests events via SDKs, an HTTP API, and Segment-proxy compatibility, then fans them out to destinations: warehouses including ClickHouse, BigQuery, Snowflake, Redshift, Postgres, S3, and GCS, and SaaS tools including PostHog, GA4, and Meta. Delivery is real-time, with per-destination batches as frequent as every minute, and you can apply JavaScript transformation functions in flight. It also carries a built-in identity graph for profile building, live event debugging, and connector syncs for pulling third-party data. The self-hosted edition has no feature gating; Jitsu Cloud is the managed tier and includes a free plan. Open source: yes (MIT); self-hostable; free (open-core).
Event data is the substrate a GTM stack runs on — product usage, site behavior, signup and conversion events — and Segment is the default way to collect and route it, at a price that scales painfully with volume. Jitsu is the open-source, self-hostable version of that job: capture events once and route them to your warehouse and to the tools your team already uses (PostHog, GA4, Meta), without per-event vendor billing and without data leaving infrastructure you control. The honest read: this is open-core, so the free path is either self-hosting (real infrastructure — a ClickHouse-backed pipeline is not zero-ops) or the jitsu.com managed tier; and the destination catalog and real-time claims are the vendor's, so verify that the specific warehouses and SaaS destinations you depend on are supported at the latency you need before you route production traffic through it.