Manage your data with these 3 open source ETL tools

If your job duties include data management and integration, you probably have used ETL tools. ETL is an acronym of three of the most important and vital database processes: Extract, Transform, and Load. An ETL tool essentially extracts data from outer sources, transforms it in accordance with the business and operational needs, and loads the transformed data to the target databases. This entire process is divided into three phases. And these three phases execute in parallel to make the entire process quick and easy.

ETL process: Extract, Transform, Load
Applied Informatics


During extraction, the required data from the source systems are identified and extracted from either a single source or from multiple sources based on the requirement. All data collected from multiple sources is consolidated into a single data warehouse, which will then undergo transformation process.


This process is meant to transform or convert the source data to the required format. This transformation involves a series of rules and functions to get the desired form of data. Some of the tasks that are performed in data transformation are applying business rules, cleaning of data, mapping, filtering, and transposing rows and columns of data.


After all the essential transformation of data is done, it is then loaded into the source data warehouse or data repository from where it will be used.

Since their inception, ETL tools have been gaining popularity, and the majority of the industry now uses some ETL tools for data integration and handling. These tools offer a structured and systematic way of data integration and give a visual flow of data, making it easy to use and operate. ETL tools let you do impact analysis while also aiding in data lineage.

There are a lot of ETL providers in the market. Here are three of the most feature-packed, easiest to use, and most reliable open-source ETL tools you should be using.

Talend Open Studio

Talend is considered to be one of the best providers of open-source ETL tools for organizations of all shapes and sizes. Talend Open Studio consists of a set of open-source tools and software that aid in development, testing, deployment, and data management. What makes Talend unique is that it provides a unified environment throughout the life cycle of a project. This makes both data management and data integration considerably easy to use and understand.

Talend uses a code-generation approach in data handling, and comes with an Eclipse-based graphical user interface. Talend aids in easy data modelling with drag-and-drop functionality for ease of usage. Talend uses a unified data repository for storing the metadata, which makes it very easy to reuse or map the data. Talend also offers a broad range of connectivity support, with over 900 components and built-in connectors. This allows you to easily connect multiple sources and targets such as data warehouses, OLAP applications, cloud-based applications, web services, file systems, and more.

Talend Open Studio

Talend also provides strong and reliable ETL functionalities. The tool comes with robust string manipulation functions, real-time data manipulations, automatic look-up handling, and more. Talend is a commercial open-source application; there is a charge for all its services except for the free initial download of the tool.


  • Easily adaptable and user-friendly tool, offering an easy integration solution for many companies
  • Provides flexible software solutions to fit various business models
  • A large number of connectors helps to develop various application business logics under a common roof


  • Most features are available only on the commercial enterprise edition
  • Java code generation can sometimes get off-sync
  • Large data processing is time consuming

Pentaho Data Integration

Pentaho data-integration is an open-source commercial business intelligence suite that has its own data integration tool known as Kettle. Pentaho’s Kettle is similar to most of the other ETL tools and runs on Java (Swing). What makes this tool unique is that storage and transformation of data are carried out in separate modules, and each of these modules is stored in XML format. Storing in XML format is an added advantage for faster data retrieval and also aids in indexing of data.

Pentaho ETL Tool

Pentaho Kettle offers an easy-to-use graphical user interface with a very simple and intuitive way to analyze data. The tool is powered by a JavaScript engine, which takes care of the data manipulation process. All the procedures of data extraction, transformation, and loading in Kettle can be executed outside the Pentaho platform using all the supported Kettle libraries and Java interpreters in the target system.

Some of the primary features of Pentaho Kettle are it allows migration of data between applications and databases, exporting flat files from databases, easy drag-and-drop data integration, agile view for data modelling, and an integrated data scheduler for coordinating workflows.


  • Very simple and intuitive to use
  • Supports customized SQL queries, JavaScript, and regular expressions
  • Good report generations and cost analysis


  • Limited functionalities and features
  • Very heavy software that consumes a lot of processing power and system memory


CloverETL is an open-source Java-based ETL tool developed and directed by OpenSys, a company based in the Czech Republic. Since CloverETL’s framework is based on Java, it is independent and is also very efficient in resource utilization.

CloverETL benefits

CloverETL allows you to efficiently develop, deploy, and automate the process of data transformations. The tool also provides an effective blend of visual transformations and workflows with full-fledged coding customization and automation abilities. CloverETL can transform, cleanse, unify, and distribute data to different types of targets such as applications, database, and warehouses. It is a component-based structure and can be used as a standalone system, command-line application, server application, and can even embed with other applications.

CloverETL contains an engine, a dedicated designer, and a server. The CloverETL engine is meant for data transformation at runtime and also acts as a library. The CloverETL designer, on the other hand, is meant to enhance the data visualization, and the CloverETL server offers a rich web-based administrative interface and aids in various functionalities such as data clustering, parallel data transformation, and more.


  • Powerful workflow engine with support for triggering, scheduling, and monitoring
  • Real-time data loading, uploading, and extraction
  • Powerful data cleansing


  • Unavailability of a debugger
  • The tool is more suitable for small and mid-sized enterprises

In addition to the three tools mentioned here, there are several other powerful open-source tools available in the market, including KETL, Scriptella, and GeoKettle. All these tools have eased the process of data integration and data management to a great extent. Most of these tools are cross-platform compatible and offer integration with multiple data sources and applications.

Featured Image Credit: Pixabay

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9 thoughts on “Manage your data with these 3 open source ETL tools”

    1. Sukesh Mudrakola


      Astera’s Centerprise is although one of the most easy to use tool with a long-list of features, it still has its own drawbacks such as,
      – The tool is not as performant as the ones mentioned above. That said, it might take upto hours to process a workflow for large datasets.
      -The tools lacks a proper metadata management and dashboards for quick reference
      -Lack of debugging capabilities
      These are some of the primary reasons, why the tool isn’t included here in my post.

      Hope this helps.

  1. I’m comparing few open source big data integration tools, what’s your opinion about Apatar? Would you suggest any other open source data integration tool?

    1. Sukesh Mudrakola

      Hello Pooja,

      Apatar is a stable opensource tool and offers good integration options and ease of usage. However, Talend offers better features and is robust.


  2. Hey,

    Nice write up!!! But it would be great if you add one more tool in this list! . Windsor software is a very useful business intelligence tool that enable an organisation to visually analyse its data to make profitable business related decisions. It helped me a lot in making my organisation’s data more informative and valuable.

  3. Hi Sukesh,

    Nice blog & comaprison. I am looking for open source data migration testing tool.
    Can you suggest me any open source tool for Data Migration testing (Oracle DB to AWS MySQL DB).

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