OPML to JSON Converter: Convert OPML to JSON Online

OPML files are useful for organizing RSS feeds, podcast subscriptions, blog lists, and other hierarchical information. The problem is that an OPML file is based on XML and can become difficult to read when it contains many folders and feed entries. If you want to inspect, organize, or work with that information in a simpler structured format, converting OPML to JSON can make the data much easier to understand.

The CalculatorKits OPML to JSON Converter is designed for this exact task. You can upload an OPML file, paste OPML content into the input area, load an example, validate the document, and convert the information into structured JSON.

The tool also provides useful information about the converted file. You can see folders, total feeds, nested categories, duplicate feeds, empty categories, and a health score. The generated JSON can be viewed as code or as a tree, then copied, downloaded, or beautified.

Whether you have an RSS subscription export, a podcast feed list, or another OPML outline, the OPML to JSON Converter gives you a convenient way to inspect the structure without manually rebuilding it.

Quick Answer: What Is an OPML to JSON Converter?

An OPML to JSON Converter changes information stored in an OPML document into structured JSON.

OPML stands for Outline Processor Markup Language. It is an XML based format designed for hierarchical outlines. It is commonly associated with lists of RSS feeds, podcast subscriptions, blogs, and other organized collections.

JSON, or JavaScript Object Notation, uses objects, arrays, keys, and values to represent structured information.

For example, an OPML document can contain a folder such as:

<outline text="Technology Blogs">
    <outline
        text="TechCrunch"
        type="rss"
        xmlUrl="https://techcrunch.com/feed/"
        htmlUrl="https://techcrunch.com/" />
</outline>

A JSON representation can look like:

{
  "text": "Technology Blogs",
  "title": "",
  "type": "folder",
  "children": [
    {
      "text": "TechCrunch",
      "title": "",
      "type": "rss",
      "xmlUrl": "https://techcrunch.com/feed/",
      "htmlUrl": "https://techcrunch.com/"
    }
  ]
}

The exact structure depends on the OPML document and the way its folders, feeds, and attributes are represented.

The CalculatorKits OPML to JSON Converter handles this conversion online and presents the result in a readable format.

Why Convert OPML to JSON?

OPML is excellent for representing hierarchical information, but the raw XML structure can be difficult to inspect manually.

A typical feed subscription file may contain several folders, dozens or hundreds of feeds, feed URLs, website URLs, titles, and other attributes. Opening that file in a basic text editor can leave you looking at a large amount of XML markup.

JSON provides a different way to view the same information.

Folders can be represented as objects. Feed collections can appear as arrays. Feed information can be represented through named properties such as text, title, type, xmlUrl, and htmlUrl.

This can make the information easier to inspect.

An OPML to JSON Converter can be useful when you want to:

• Inspect an OPML subscription file
• Understand its folder structure
• Review individual feeds
• Find duplicate feed entries
• See nested categories
• Convert OPML into a more familiar structured format
• Create a readable representation of an OPML file
• Copy the resulting JSON
• Download the converted JSON
• Check whether an OPML document is valid before conversion

The biggest advantage is convenience. Instead of manually reading XML elements and attributes, you can see the information organized into JSON objects and arrays.

Who Can Use an OPML to JSON Converter?

The OPML to JSON Converter is useful for more than one type of user.

RSS Feed Users

People who maintain large RSS collections can use the converter to inspect their exported subscription lists.

If your feed reader provides an OPML export, converting it to JSON can make the folder and feed structure easier to examine.

Podcast List Managers

OPML is also used to move podcast subscriptions between compatible applications. A JSON version can provide a convenient structured view of the subscription information.

Bloggers and Content Researchers

Anyone maintaining a collection of blogs or websites can use an OPML file to organize feeds. Converting that file to JSON can make the structure easier to review.

Students

Students learning XML, OPML, and JSON can use the converter to see how the same hierarchical information changes between formats.

Developers and Technical Users

People working with structured files can use the OPML to JSON Converter when they need a readable JSON representation of an OPML document without manually rewriting its contents.

OPML to JSON Conversion Workflow

The basic process is simple:

Prepare your OPML file
        ↓
Upload or paste OPML
        ↓
Validate the OPML
        ↓
Review the structure
        ↓
Convert to JSON
        ↓
Inspect the JSON output
        ↓
Check the feed summary
        ↓
Review duplicate feeds
        ↓
Copy or download JSON

The CalculatorKits interface combines conversion with useful information about the source file. This means you can do more than simply generate JSON.

You can also inspect the structure of your feed collection.

How to Use the OPML to JSON Converter

1. Prepare Your OPML File

Start with an OPML file.

An OPML document may look something like this:

<?xml version="1.0" encoding="UTF-8"?>
<opml version="2.0">
  <head>
    <title>Example Feeds</title>
  </head>
  <body>
    <outline text="Technology Blogs">
      <outline
        text="TechCrunch"
        type="rss"
        xmlUrl="https://techcrunch.com/feed/"
        htmlUrl="https://techcrunch.com/" />
    </outline>
  </body>
</opml>

A larger file may contain several folders and many feeds.

You do not need to manually change the XML before using the converter.

2. Upload Your OPML File

Open the CalculatorKits OPML to JSON Converter.

The interface provides a large drag and drop area for OPML files.

You can drag your file into this area or select Browse Files.

The interface indicates support for .opml, .xml, and .txt files.

This makes the upload process useful even if your OPML content has been saved with a different file extension.

3. Paste OPML Content

If you do not want to upload a file, you can also enter OPML directly into the OPML Input area.

This is useful when you already have the XML content available and only want to convert a specific section or example.

For a large OPML file, uploading the document is usually more convenient.

4. Load an Example

The Example button lets you load sample OPML content into the input area.

The sample shown in the CalculatorKits interface contains several categories and RSS feeds. It includes folders such as Technology Blogs and News, along with feed information such as the feed URL and website URL.

This makes the example useful for understanding what the converter does before using your own file.

5. Validate Your OPML

Before conversion, you can use the Validate button.

The interface displays a clear status when the OPML is valid.

For example:

✓ Valid OPML

Validation is useful because an invalid or incomplete OPML document may not produce the structure you expect.

Checking the source before conversion can save time, especially when working with a file exported from another application.

6. Convert OPML to JSON

Once your OPML is ready, the converter processes the document and creates structured JSON.

The output shown by CalculatorKits uses an outlines array to represent the hierarchical information.

A simplified result can look like:

{
  "outlines": [
    {
      "text": "Technology Blogs",
      "title": "",
      "type": "folder",
      "children": [
        {
          "text": "TechCrunch",
          "title": "",
          "type": "rss",
          "xmlUrl": "https://techcrunch.com/feed/",
          "htmlUrl": "https://techcrunch.com/"
        }
      ]
    }
  ]
}

This structure makes the relationship between folders and feeds much easier to see.

7. Review the JSON Output

The JSON Output section displays the generated result.

You can view the output in Code mode or switch to Tree mode.

Code view is useful when you want to read or copy the JSON itself.

Tree view can be useful when you want to understand the hierarchy visually.

The converter also provides Copy, Download, and Beautify options.

8. Check the Feed Summary

One of the useful features of the CalculatorKits OPML to JSON Converter is its Feed Summary section.

The interface can display information such as:

• Folders
• Total Feeds
• Nested Categories
• Duplicate Feeds
• Empty Categories
• Health Score

For example, the sample interface shows:

Folders: 3
Total Feeds: 14
Nested Categories: 1
Duplicate Feeds: 0
Empty Categories: 0
Health Score: 100%

This gives you a quick overview of the source file.

Instead of manually counting folders and feeds, you can see the basic structure at a glance.

OPML to JSON Example

Consider a simple OPML document:

<?xml version="1.0" encoding="UTF-8"?>
<opml version="2.0">
  <head>
    <title>My Feeds</title>
  </head>
  <body>
    <outline text="Technology">
      <outline
        text="TechCrunch"
        type="rss"
        xmlUrl="https://techcrunch.com/feed/"
        htmlUrl="https://techcrunch.com/" />
      <outline
        text="The Verge"
        type="rss"
        xmlUrl="https://www.theverge.com/rss/index.xml"
        htmlUrl="https://www.theverge.com/" />
    </outline>
  </body>
</opml>

A JSON representation can look like:

{
  "outlines": [
    {
      "text": "Technology",
      "title": "",
      "type": "folder",
      "children": [
        {
          "text": "TechCrunch",
          "title": "",
          "type": "rss",
          "xmlUrl": "https://techcrunch.com/feed/",
          "htmlUrl": "https://techcrunch.com/"
        },
        {
          "text": "The Verge",
          "title": "",
          "type": "rss",
          "xmlUrl": "https://www.theverge.com/rss/index.xml",
          "htmlUrl": "https://www.theverge.com/"
        }
      ]
    }
  ]
}

The important point is that the hierarchy remains visible.

The Technology folder becomes an object, while its feeds appear inside the children array.

How OPML Is Structured

Understanding OPML makes the conversion easier to follow.

The OPML Root

An OPML document normally begins with an opml element.

For example:

<opml version="2.0">

This identifies the document as an OPML document.

The Head Section

The head section can contain information about the OPML document.

For example:

<head>
  <title>Example Feeds</title>
</head>

The title provides information about the document itself.

The Body Section

The body contains the outline information.

This is where folders and individual feeds are usually found.

For example:

<body>
  <outline text="Technology">
    ...
  </outline>
</body>

Outline Elements

The outline element is central to OPML.

An outline can represent a category, folder, feed, or another hierarchical item.

For example:

<outline text="Technology Blogs">

can act as a folder containing other outline elements.

Feed Attributes

An RSS feed outline may contain attributes such as:

<outline
  text="TechCrunch"
  type="rss"
  xmlUrl="https://techcrunch.com/feed/"
  htmlUrl="https://techcrunch.com/" />

These attributes contain useful information about the feed.

When converted to JSON, they can appear as properties of an object.

How the OPML to JSON Converter Represents Folders

One of the most useful parts of the conversion is the way hierarchical folders can be represented in JSON.

A folder might become:

{
  "text": "Technology Blogs",
  "title": "",
  "type": "folder",
  "children": []
}

The children property can then contain the feeds or nested folders inside that category.

For example:

{
  "text": "Technology Blogs",
  "type": "folder",
  "children": [
    {
      "text": "TechCrunch",
      "type": "rss"
    },
    {
      "text": "The Verge",
      "type": "rss"
    }
  ]
}

This makes the hierarchy easier to understand than reading several levels of nested XML tags.

How the OPML to JSON Converter Handles RSS Feeds

RSS feed entries commonly contain information such as the feed name, feed type, XML feed URL, and website URL.

For example:

{
  "text": "TechCrunch",
  "title": "",
  "type": "rss",
  "xmlUrl": "https://techcrunch.com/feed/",
  "htmlUrl": "https://techcrunch.com/"
}

The exact properties depend on the information available in the source OPML.

If an OPML file contains additional attributes, the resulting JSON may include corresponding information.

This is one reason JSON can be convenient for inspecting a feed collection.

Instead of reading XML attributes inside a long document, you can see the information as named JSON properties.

Understanding Folders, Feeds, and Nested Categories

An OPML subscription list may not be flat.

You might have:

Technology
    TechCrunch
    The Verge

News
    BBC News
    Hacker News

Podcasts
    Technology Podcast
    News Podcast

A JSON representation can preserve this hierarchy.

A folder can contain a children array. That array can contain individual feeds or additional folders.

This is particularly helpful when your OPML file contains many categories.

The CalculatorKits OPML to JSON Converter also provides a summary of folders and nested categories, making it easier to understand the overall organization.

Duplicate Feeds and Feed Cleanup

Large OPML files can sometimes contain duplicate feed entries.

The CalculatorKits interface includes a Duplicate Feeds Detected section when duplicates are found.

The screenshot shows duplicate entries such as a feed URL appearing more than once.

For example, a duplicate may be identified like this:

https://techcrunch.com/feed/ appears 2 times

The interface also provides a Remove All Duplicates button.

This is useful when your subscription list has grown over time or has been combined from multiple sources.

Removing duplicates can make the resulting JSON cleaner and easier to inspect.

If you want to preserve every original entry exactly as it appeared in the source file, review duplicates before removing them.

Feed Summary and Health Score

The Feed Summary section gives you a quick overview of the OPML document.

It can show:

Folders
Total Feeds
Nested Categories
Duplicate Feeds
Empty Categories
Health Score

This information can help you identify potential problems before you work with the converted JSON.

For example, a file with many duplicate feeds may benefit from cleanup.

An OPML file with empty categories may indicate that some folders no longer contain subscriptions.

The health score shown by the CalculatorKits interface provides another quick indicator of the condition of the imported feed collection.

It should be treated as a helpful summary rather than a replacement for reviewing the actual file.

OPML to JSON Converter Accuracy and Limitations

The OPML to JSON Converter is most useful when the source is a valid and reasonably structured OPML document.

The conversion does not change the fundamental information into something completely different. Instead, it represents the existing OPML hierarchy and attributes in JSON.

However, different OPML files may contain different structures.

Some may contain only a few feeds.

Others may contain several folders, nested categories, feed attributes, titles, URLs, and additional outline information.

The output should therefore be reviewed after conversion.

A successful conversion means the tool was able to process the source. It does not necessarily mean that every piece of information is organized exactly the way you personally want.

This is especially important for unusual OPML documents.

Always keep your original file before making changes such as removing duplicates.

Common OPML to JSON Conversion Problems

Invalid OPML

An OPML document with malformed XML can cause validation problems.

Use the Validate option before conversion when possible.

Missing Feed Information

Some outline entries may not contain all expected feed attributes.

The resulting JSON reflects the information available in the source.

Empty Categories

An OPML file may contain folders that do not contain any feeds.

The Feed Summary can help identify empty categories.

Duplicate Feeds

The same feed may appear more than once.

Review the Duplicate Feeds Detected section before removing anything.

Deeply Nested Categories

Some OPML files contain several levels of folders.

Tree view can be particularly useful when reviewing this type of structure.

Large OPML Files

A large subscription collection can contain hundreds or thousands of entries.

For large files, uploading the document is generally more convenient than pasting the entire content into the input box.

Unexpected Outline Structures

OPML can be used for hierarchical information beyond simple RSS subscriptions.

If your document uses unusual outline structures, review the generated JSON carefully.

How to Check Your Converted JSON

After using the OPML to JSON Converter, take a moment to inspect the output.

First, check whether the main outlines structure is present.

Next, look at the folders and their children arrays.

Then inspect individual feed objects.

Check properties such as:

text
title
type
xmlUrl
htmlUrl

Your particular OPML document may contain additional information.

Tree view can help when the JSON contains many nested levels.

Code view is useful when you want to copy or save the actual JSON.

The Feed Summary provides another quick way to compare the structure of the source with what you expected.

Beautify, Copy, and Download JSON

The CalculatorKits output area includes several useful controls.

Beautify

Beautify makes the JSON easier to read by adding indentation and line breaks.

This is particularly useful for large feed collections.

Copy

The Copy button lets you copy the generated JSON.

This is useful when you want to paste the result into another editor or document.

Download

The Download button lets you save the converted JSON as a file.

This is convenient when you want to keep the result alongside the original OPML document.

Code and Tree Views

Code view shows the JSON itself.

Tree view provides a more visual way to explore the hierarchy.

For a small file, either view may work well. For a large nested OPML document, Tree view can make the structure easier to follow.

When Is an OPML to JSON Converter Useful?

There are several practical situations where this tool can save time.

Managing RSS Subscriptions

If you have exported your RSS subscriptions as OPML, converting the file to JSON can make the collection easier to inspect.

Organizing Podcast Subscriptions

Podcast applications can use OPML for subscription exports. A JSON representation can provide another way to examine the collection.

Reviewing Blog Lists

Blog and website feed collections can become large over time. JSON provides a convenient structured view of the folders and feeds.

Learning About OPML

If you are learning how OPML works, converting a real file into JSON can help you understand its hierarchy.

Checking Duplicate Feeds

The CalculatorKits interface can identify duplicate feed URLs and display them separately.

Exploring Folder Structures

The Feed Summary and Tree view can make nested categories easier to understand.

Tips for Better OPML to JSON Conversion

Keep a copy of your original OPML file.

Validate the OPML before conversion.

Use the Example option if you are new to the tool.

Review the number of folders and feeds.

Check nested categories.

Look for duplicate feeds.

Review empty categories.

Inspect the generated JSON.

Use Tree view for complicated structures.

Use Beautify when readability matters.

Download the result if you need a permanent copy.

Do not remove duplicate feeds until you are sure they are unnecessary.

These small steps can make the conversion process much safer and easier.

Frequently Asked Questions

What is an OPML to JSON Converter?

An OPML to JSON Converter changes the structured information in an OPML document into JSON. It can represent folders, feeds, nested categories, and feed attributes as JSON objects and arrays.

How do I convert OPML to JSON online?

Open the CalculatorKits converter, upload your OPML file or paste the OPML content, validate it, and convert it to JSON. You can then review, copy, beautify, or download the result.

Can I upload an OPML file?

Yes. The CalculatorKits interface provides a drag and drop upload area and a Browse Files button.

Which file types are supported?

The interface indicates support for .opml, .xml, and .txt files.

Can I paste OPML instead of uploading a file?

Yes. You can enter OPML directly into the OPML Input area.

Can I validate my OPML before conversion?

Yes. The Validate button allows you to check the OPML before converting it.

What does the Example button do?

The Example button loads sample OPML content so you can see how the converter works.

Can an OPML file contain folders?

Yes. OPML can represent hierarchical information through nested outline elements. The CalculatorKits converter can represent these structures in the generated JSON.

Can an OPML file contain RSS feeds?

Yes. OPML is commonly used for collections of RSS feeds. Feed entries can contain information such as feed names and URLs.

Can the converter show duplicate feeds?

Yes. The CalculatorKits interface includes a Duplicate Feeds Detected section when duplicate entries are identified.

Can I remove duplicate feeds?

The interface shown for the tool provides a Remove All Duplicates option.

Review the duplicates before removing them if you need to preserve the original subscription list.

What is the Feed Summary?

The Feed Summary provides an overview of the imported OPML file. It can show folders, total feeds, nested categories, duplicate feeds, empty categories, and a health score.

Can I view the JSON as a tree?

Yes. The output section provides Code and Tree views.

Can I beautify the JSON?

Yes. The Beautify button formats the JSON to make it easier to read.

Can I copy the converted JSON?

Yes. The Copy button lets you copy the generated JSON.

Can I download the JSON?

Yes. The Download button lets you save the converted JSON.

Does the converter work with large OPML files?

The CalculatorKits interface specifically presents the tool as supporting large OPML files. For very large documents, uploading the file is more practical than manually pasting the content.

Does every OPML file produce the same JSON structure?

No. The result depends on the structure and information contained in the source OPML document.

Should I keep the original OPML file?

Yes. Keeping the original is a good practice, especially if you plan to clean duplicates or make other changes to the converted information.

Related CalculatorKits Tools

If you regularly work with structured data, these related CalculatorKits tools may also be useful.

The XML to JSON Converter can help when you have ordinary XML data and want to convert it into JSON.

The JSON to XML Converter is useful when you need to convert JSON into an XML document.

The JSON to Text Converter can help when you want to turn JSON into a readable text representation.

The Text to JSON Converter is useful when your starting information is structured plain text and you want to create JSON from it.

The JSON to CSV Converter can help when structured JSON needs to be represented as rows and columns.

References and Further Reading

For information about OPML and its specifications, see the OPML.org documentation.

For information about XML, see the W3C XML documentation.

For information about JSON syntax and data interchange, see the IETF JSON specification.

For a simple introduction to JSON, see JSON.org.

For the actual conversion tool and its available features, see the CalculatorKits OPML to JSON Converter.

Key Takeaways

The OPML to JSON Converter provides a simple way to transform an OPML document into structured JSON.

CalculatorKits lets you upload an OPML file, drag and drop it into the tool, or paste OPML content directly into the input area. The interface supports OPML, XML, and TXT files.

Before conversion, you can validate the source document. After conversion, the generated JSON can be viewed in Code or Tree mode.

The tool also provides useful information about the source file through its Feed Summary. You can see folders, total feeds, nested categories, duplicate feeds, empty categories, and a health score.

Duplicate feed detection is particularly useful for large subscription collections. If the same feed appears multiple times, the interface can identify those entries and provides an option to remove all duplicates.

The OPML to JSON Converter is useful for RSS subscription lists, podcast collections, blog feeds, hierarchical outlines, learning, and general structured data work.

For the best results, keep your original OPML file, validate the source before conversion, review the folder and feed summary, check duplicate entries, inspect the generated JSON, and use Tree view when the structure becomes difficult to follow.

Once you are satisfied with the result, you can beautify the JSON, copy it, or download it for later use.

Written and reviewed by the CalculatorKits Editorial Team

Last Updated: August 31, 2026