JSON vs OPML Outline: Which Should You Use?

Side-by-side comparison of JSON and OPML Outline data formats — features, pros, cons, and conversion options.

Quick Answer

JSON is best for Web APIs, configuration files, and structured data interchange. OPML Outline is best for Importing and exporting RSS feed subscription lists between readers.

Quick Verdict

JSON Best for Web APIs, configuration files, and structured data interchange
  • Native to JavaScript and web APIs
  • Supports nested and typed data
  • Universally supported across all languages
  • No comments allowed
OPML Outline Best for Importing and exporting RSS feed subscription lists between readers
  • Standard for exchanging RSS feed subscriptions
  • Simple hierarchical outline structure
  • Supported by all major feed readers
  • Limited to outline/subscription data
Convert OPML Outline to JSON →

Specs Comparison

Side-by-side technical comparison of JSON and OPML Outline

Feature JSON OPML Outline
Category Data Data
Year Introduced 2001 2000
MIME Type application/json text/x-opml
Extensions .json .opml
Plain Text
Typed
Nested
Human Readable
Schema Support
Streaming
Binary Efficient

Pros & Cons

JSON

Pros
  • ✓ Native to JavaScript and web APIs
  • ✓ Supports nested and typed data
  • ✓ Universally supported across all languages
Cons
  • ✗ No comments allowed
  • ✗ Verbose for large datasets
  • ✗ No date or binary type

OPML Outline

Pros
  • ✓ Standard for exchanging RSS feed subscriptions
  • ✓ Simple hierarchical outline structure
  • ✓ Supported by all major feed readers
Cons
  • ✗ Limited to outline/subscription data
  • ✗ Rarely used outside RSS context
  • ✗ XML-based verbosity

When to Use Each

Choose JSON when...

  • You need files optimized for Web APIs, configuration files, and structured data interchange
  • Native to JavaScript and web APIs
  • Supports nested and typed data

Choose OPML Outline when...

  • You need files optimized for Importing and exporting RSS feed subscription lists between readers
  • Standard for exchanging RSS feed subscriptions
  • Simple hierarchical outline structure

How to Convert

Convert between JSON and OPML Outline for free on ChangeThisFile

Convert OPML Outline to JSON Runs in your browser — files never leave your device

Frequently Asked Questions

JSON is best for Web APIs, configuration files, and structured data interchange, while OPML Outline is best for Importing and exporting RSS feed subscription lists between readers. Both are data formats but they differ in compression, compatibility, and intended use cases.

It depends on your use case. JSON is better for Web APIs, configuration files, and structured data interchange. OPML Outline is better for Importing and exporting RSS feed subscription lists between readers. Consider your specific requirements when choosing between them.

Direct conversion from JSON to OPML Outline is not currently available on ChangeThisFile. You may need to use an intermediate format.

Yes. ChangeThisFile supports OPML Outline to JSON conversion. The conversion runs in your browser with no upload required.

File size varies depending on the content, compression method, and quality settings of each format. In general, lossy formats produce smaller files than lossless ones. Test with your specific files to compare actual sizes.

JSON and OPML Outline share some features but differ in others. Check the feature comparison table above for a detailed side-by-side breakdown.

Both JSON and OPML Outline are supported file formats that are free to use. You can convert between them for free on ChangeThisFile — browser-based conversions have no limits and your files never leave your device.

JSON is newer — it was introduced in 2001, while OPML Outline dates back to 2000. Newer formats often offer better compression and features, but older formats tend to have wider compatibility.

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