Esper vs Estuary
Esper
espertech.comEstuary
estuary.devSide by side
| Figure | Esper | Estuary |
|---|---|---|
| Price from | Free | $0.50/mo |
| Free plan | Yes | Yes |
| Free trial | — | Yes |
| Open source | Yes | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 5 | 9 |
| Spec score · Stream Analytics Software | 8.7 (#4) | 9.0 (#3) |
| Documentation depth | EsperTech publishes reference manuals, API JavaDocs, examples, training material and a knowledge base across many releases. | Connector references include prerequisites, configuration properties, YAML examples, supported features and SaaS resource lists. |
| Founded | Esper is documented as created in 2006, with its first public release in early 2006. | Estuary says it was founded in 2019. |
| Headquarters | EsperTech lists a mailing address in Wayne, New Jersey, USA. | New York City, New York, United States |
| Integrations | The feature list names CSV, JMS, HTTP, Kafka, database and socket input/output adapters, and JMX metrics exposure. | Estuary advertises more than 200 prebuilt connectors across databases, warehouses, SaaS apps, and cloud platforms, including Snowflake, BigQuery, Kafka, MySQL, and PostgreSQL. |
| Licence | The open-source Esper and NEsper code is released under the GNU GPL version 2. | The Estuary Flow runtime uses Business Source License 1.1, forbids operating a third-party data-processing service, and is scheduled to change to Apache 2.0 on 2029-11-20; the connector repository is dual MIT/Apache 2.0. |
| Support | Commercial support is offered on 24x7 or 8x5 schedules through phone, email or a web portal. | The Cloud plan includes standard support through community Slack and email; Enterprise includes dedicated Slack and email support. |
| What it does | Esper is a language, compiler and runtime for complex event processing and streaming analytics. | Estuary is a right-time data platform that captures data once and delivers it to warehouses, operational systems, applications and AI workflows using CDC, streaming, ETL/ELT and scheduled movement. |
Plans
Esper
- Esper 9.0.0Free
- Esper Open SourceFree
- Esper Enterprise EditionPriced on request
- EsperHAPriced on request
- Esper supportPriced on request
Estuary
- FreeFree
- Pay-as-you-go$100 a month
- AnnualPriced on request
- DeveloperFree
- FreeFree
- Cloud$0.50 a month
- Cloud PAYG$0.50 a month
- EnterprisePriced on request
- Private/BYOCPriced on request
In their own words
Esper
Esper is a language, compiler, and runtime for complex event processing and streaming analytics in Java and .NET. Its Event Processing Language extends SQL with expressions over events and time. The compiler turns EPL into bytecode that can be packaged in JAR files. Esper and NEsper embed inside Java or .NET processes rather than running as standalone servers. The in-memory runtime is described as memory-efficient and low-latency and does not require external storage or services. Adapters handle CSV, JMS, HTTP, Kafka, database, and socket input and output, with JMX metrics exposure. Queries can join event streams with web services and relational databases through SQL-query or method-invocation joins. Esper Enterprise Edition adds scale-out architecture with elastic scaling, load balancing, fault tolerance, and multi-datacenter support using Apache Kafka and Apache Zookeeper. Listed uses include business-process monitoring, financial applications such as fraud detection, network and application monitoring, and sensor networks. Esper 9.0.0 is listed under GNU GPL (GPL v2); commercial redistribution licenses are available. Production support has Bronze, Silver, and Gold levels, plus a Developer Seat for how-to questions.
Estuary
Estuary is a managed data integration platform for combining change data capture, batch, streaming, and app synchronization for analytics, operations, and AI. It supports transformations while data is moving, using SQL, Python, or TypeScript, and describes delivery as exactly once with end-to-end latency under 100 milliseconds. More than 200 prebuilt connectors cover databases, warehouses, SaaS apps, and cloud platforms, including Snowflake, BigQuery, Kafka, MySQL, and PostgreSQL. Customers can store data in their own cloud bucket for a duration they choose, and select public, private, or Bring Your Own Cloud deployment. Estuary lists SOC 2 Type II, HIPAA, HITECH, CCPA, and GDPR among its compliance standards, and says data is encrypted in transit and at rest. It is available through API, self-hosted, and web options. The indefinite free tier is limited to 10 GB per month and two concurrent connector instances; paid plans start at $100 a month.