This is the RefinePro knowledge base about OpenRefine. We build it over the years, and keep adding to it. From great tutorials and how-to, to handy GREL expressions and links to external resources, you will find here one of the most comprehensive list of resources to learn OpenRefine.

For a comprehensive documentation you should refer to the official OpenRefine wiki.

Don't where to get started? Search for a specific function below, or read our most popular article from the right side menu.


OpenRefine January 2021 Review

2021 starts big with the release of the new user documentation for OpenRefine. It took over six months of hard work to migrate the documentation from GitHub wiki to Docusaurus. It was also the opportunity to update the content. 

We also listed below new tutorials and videos published about OpenRefine through January along with the update of the NER and RDF extensions. 

 Do not forget to subscribe to our newsletter to get our monthly update right in your mailbox.


OpenRefine: Create an empty column

 Sometimes you just need to add a new empty column to your OpenRefine project. The process is straight forward as we show in this video tutorial.

  • From any existing column select the option Edit column and then Add a column based on this column ... 
  • By default, the GREL formula repeat the value from the column you selected
  • Just replace the value with two quotes like this ""  to create an empty string. You can add any text between the quotes. OpenRefine will add it for all the rows selected by your facet.
  • Give your new column and name and click OK
  • and you are done! 
We made a quick video tutorial to show you the steps: