head to head · open source
realtime vs flink-cdc
realtime has 7,675 GitHub stars, 479 forks, 78 open issues and last shipped yesterday. flink-cdc has 6,491 stars, 2,205 forks, 119 open issues and last shipped yesterday. realtime leads on adoption by 18% (7,675 vs 6,491 stars). realtime is written in Elixir under Apache-2.0; flink-cdc is written in Java under Apache-2.0. realtime has attracted 6% as many forks as stars, flink-cdc 34%. realtime was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (cdc, change-data-capture), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| realtime | flink-cdc | |
|---|---|---|
| GitHub stars | ★ 7.7K | ★ 6.5K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Elixir | Java |
| Last push | 2026-11-04 | 2026-11-04 |
| Forks | ⑂ 479 | ⑂ 2.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick realtime if
- You weight community size — 7.7K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Elixir
- You value the larger contributor base for long-term maintenance
pick flink-cdc if
- You want the flink-cdc feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and flink-cdc fits your workflow better
About realtime
Supabase Realtime Send ephemeral messages, track and synchronize shared state, and listen to Postgres changes all over WebSockets. Examples · Request Features · Report Bugs Status This repository focuses on version 2 but you can still access the previous version's code and Docker image. For the latest Docker images go to The codebase is under heavy development and the documentation is constantly evolving. Give it a try and let us know what you think by creating an issue. Watch releases of this repo to get notified of updates. And give us a star if you like it! Overview What is this? This is a server built with…
read the full realtime overview →
About flink-cdc
Flink CDC is a distributed data integration tool for real time data and batch data, built on top of Apache Flink. It prioritizes efficient end to end data integration and offers enhanced functionalities such as full database synchronization, sharding table synchronization, schema evolution and data transformation. API Layers Flink CDC provides three API layers for different usage scenarios: 1. YAML API (Pipeline API) The YAML API provides a declarative, zero code approach to define data pipelines. Users describe the source, sink, routing, transformation, and schema evolution rules in a YAML file and submit it…
read the full flink-cdc overview →
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Frequently asked questions
Is realtime or flink-cdc more popular?
realtime has 7,675 GitHub stars and flink-cdc has 6,491. realtime has the larger community by that measure.
Are realtime and flink-cdc free?
Both are open source. realtime is licensed under Apache-2.0 and flink-cdc under Apache-2.0. Neither carries a licence fee.
What is the difference between realtime and flink-cdc?
realtime is written in Elixir and flink-cdc in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, realtime or flink-cdc?
Choose realtime if you want the larger community (7,675 stars) or its Apache-2.0 licence terms. Choose flink-cdc if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.