Best Stream Processing Software in 2026
Updated
In short: AFL++ is ranked #1 of 23 as of 4 October 2026, ahead of Apache Flink and Arroyo. The best-ranked option with a free plan is Apache Flink. The lowest first paid tier on this page is Materialize at $0.13/mo.
Stream processing software works with data as events arrive, and the listed features help you compare how each option may fit your pipelines. Check deployment model and source connectors alongside SQL processing, event-time windows, and stateful processing. Supported languages may also matter when considering what works for your team. The ranked entries begin with AFL++ and Apache Flink, followed by Confluent Cloud. Esper, Feldera, and Kafka Streams appear among the early options as well. Free-plan availability and paid-from pricing add cost context; compare those details with the processing features, connectors, and deployment choices relevant to your workloads.
23 stream processing software ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
| # | App | Score | From | Free plan | Paid from | Deployment model | SQL processing | Stateful processing | Event-time windows | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  AFL++ | 7.8 | €1666.67/mo | Yes | — | — | — | — | — | View |
| 2 | Apache Flink | 6.4 | Free | Yes | — | self-hosted | Yes | Yes | Yes | View |
| 3 | Arroyo | 6.4 | Free | — | — | hybrid | Yes | Yes | Yes | View |
| 4 | Confluent Cloud | 6.4 | $385/mo | Yes | 385 /mo | cloud | — | — | — | View |
| 5 |  Esper | 6.4 | Free | Yes | — | self-hosted | Yes | Yes | Yes | View |
| 6 |  Feldera | 6.4 | Free | Yes | — | hybrid | Yes | Yes | Yes | View |
| 7 |  Kafka Streams | 6.4 | Free | Yes | — | self-hosted | No | Yes | Yes | View |
| 8 | Materialize | 6.4 | $0.13/mo | Yes | — | hybrid | Yes | Yes | Yes | View |
| 9 |  Pathway Live Data Framework | 6.4 | Free | Yes | — | hybrid | Yes | Yes | Yes | View |
| 10 | Apache Beam | 6.3 | Free | — | — | — | — | — | — | View |
| 11 | Apache Samza | 6.3 | Free | Yes | — | self-hosted | Yes | Yes | Yes | View |
| 12 | Apache Spark | 6.3 | Free | Yes | — | — | — | — | — | View |
| 13 |  Apache Storm | 6.3 | Free | Yes | — | self-hosted | — | Yes | — | View |
| 14 |  Timeplus | 6.3 | $199/mo | No | 199 /mo | — | — | — | — | View |
| 15 | Apache NiFi | 6.2 | Free | — | — | — | — | — | — | View |
| 16 | RisingWave | 5.8 | $0.23/mo | No | — | hybrid | — | — | — | View |
| 17 | Hazelcast Platform | 5.7 | — | Yes | — | hybrid | Yes | Yes | Yes | View |
| 18 | Amazon Managed Service for Apache Flink | 5.5 | — | No | — | cloud | Yes | Yes | Yes | View |
| 19 |  Apache Kafka | 5.4 | — | Yes | — | self-hosted | No | Yes | Yes | View |
| 20 |  Siddhi | 5.4 | — | — | — | self-hosted | Yes | Yes | Yes | View |
| 21 |  Quix Streams | 5.3 | — | — | — | hybrid | No | Yes | Yes | View |
| 22 |  Timely Dataflow | 5.2 | — | — | — | self-hosted | — | Yes | — | View |
| 23 | Apache Heron | 4.7 | — | — | — | — | — | — | — | View |
Is your app on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which stream processing software is ranked first on Samsung Mobile US Press?
AFL++ is ranked #1 of 23 with a score of 7.8. Apache Flink is second and Arroyo third.
How many of these have a free plan?
15 of the 23 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Materialize has the lowest first paid tier we found: $0.13/mo.
How is this list ranked?
Ranked mobile-first: a phone app alongside the web or desktop product, a free tier and the depth of its documentation. Paid placements never change a rank.