This article describes what OPML files are, how to open one, and how to convert one to a different format like XML, HTML, CSV, etc.

What to Know

  • An OPML file is an Outline Processor Markup Language file.
  • Open one with Feedly.
  • Convert to CSV with opml2csv.com, or to HTML with Tkoutline.

What Is an OPML File?

A file with the OPML file extension is an Outline Processor Markup Language file. It’s saved in a particular structure using the XML format, and is used to exchange information between applications regardless of the operating system.

This file format is often seen used as the import/export format for RSS feed reader programs. Since an OPML file can hold a collection of RSS subscription information, it’s the ideal format for backing up or sharing RSS feeds.

How to Open an OPML File

Almost any program that manages RSS feeds should be able to import and export OPML files. Feedly is one example that can import one (log in and open the OPML Import page). The Thunderbird email client should work as well.

If you find an OPML file online and would like to see what’s in it, there’s a tool called OPML Viewer that will do just that.

Tkoutline and ConceptDraw’s MINDMAP can open it, too.

A simple text editor is another way. See our Best Free Text Editors list for some of our favorites. Remember, however, that an actual RSS feed aggregator like Feedly is the best way to actually make the OPML feed entries useful (i.e., show the content that the feeds are from). A text editor is really only good for editing the file or viewing just the text content.

On that note, any XML or text editor can be used to make changes to an OPML file.

How to Convert an OPML File

The Tkouline program mentioned above can be used to convert an OPML file to HTML or XML.

If you find that an application on your PC does try to open the file but it’s the wrong application or you’d rather have another installed program open it, see our How to Change File Associations in Windows guide to do that.

OPML files can also be converted to CSV for use in a spreadsheet program like Microsoft Excel. This online tool at opml2csv.com can do that.

Pandoc is another converter that can save the XML data from the OPML file to a huge variety of formats like AsciiDoc, markdown, LaTeX, and others.

More Information on the OPML File Format

In a typical OPML file, there’s a head element that describes the title, owner, or some other metadata information. With an RSS feed, this is normally the article’s title. Following that is the body tag that holds the content of what the file is describing, and the outline element to hold attributes or other outline sub-elements.

OPML was created by UserLand with the original intent being for a file format that belonged to the word processor tool built into the Radio UserLand software.

Still Can’t Open It?

If you can’t open your file with the suggestions from above, the first thing you should check is that you’re actually dealing with an OPML file. Some file extensions look similar but are in fact not related at all, and therefore don’t work with the programs above.

For example, you might really have an OMP file, which could be an Office Manager Document Archive file or an OpenMind Window Document file. Although the extension looks an awful lot like OPML, they aren’t the same format and can’t open with the same applications. The former is a format created by the Krekeler Office Manager Pro software, and the latter works with MatchWare MindView.

OPAL is similar; it’s used by Microsoft Office Customization Tool as a Microsoft Office User Settings file to customize how MS Office is installed.

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