Open Source Alternatives to Power Query & M

To find a true "open source" equivalent to Power Query, we have to split it into its two distinct identities: the Visual Interface (the low-code ETL tool) and the M Language (the functional data transformation engine).

There is no single "clone" that does both exactly like Microsoft, but these are the best open source tools that replicate the specific workflows.

1. The Visual Alternatives

(Replacing the Power Query Editor)

If you want the drag-and-drop, "Applied Steps" experience where you build a transformation recipe without writing code, these are the strongest candidates.

Apache Hop

• The Experience: A "visual development" environment. Instead of a list of steps on the right side, you build a flowchart (pipeline) of actions. You drag a CSV Input block, connect it to a Filter Rows block, and then to a Table Output block.
• Why it's like Power Query: It is purely metadata-driven. You don't write code; you configure "transforms" just like you configure the gear icons in Power Query steps. It allows you to preview data at every "hop."
• Origin: A fork of the famous generic ETL tool Kettle (Pentaho), designed to be modern and project-centric.

KNIME Analytics Platform

• The Experience: Uses a node-based workflow. You drag nodes onto a canvas to perform tasks like "Row Filter," "Group By," or "Join."
• Why it's like Power Query: It visualizes the data flow explicitly. In Power Query, your steps are hidden in a list; in KNIME, they are a visible map. You can execute a node and immediately see the data table at that specific stage (like clicking a previous step in "Applied Steps").

OpenRefine

• The Experience: A spreadsheet-like interface running in your browser.
• Why it's like Power Query: Designed specifically for messy data. It has an "Undo/Redo" history that functions almost exactly like the "Applied Steps" list. It excels at replace values, split column, and cluster and edit (fuzzy matching).

2. The Code Alternatives

(Replacing the M Language)