An Overview of RSS and Feed Standards

RSS has been around for decades, but it is still one of the simplest and most powerful ways to follow content online. But working with it is not easy, over the years there were a lot of developments that added new parts to the existing standarts. I tried to collect every relevant standart and protocoll.

RSS 2.0

RSS 2.0 is the most widely adopted version of the RSS format, originally developed by Dave Winer and supported by the RSS Advisory Board.

• Uses XML for content distribution.
• Supports enclosures (e.g., for podcasts).
• Simple and human-readable.

Specs:

• Harvard RSS 2.0 Spec
• RSS Advisory Board Spec

RSS 1.0 (RDF-based)

RSS 1.0 is an older version based on RDF (Resource Description Framework), enabling richer semantic metadata.

• More complex than RSS 2.0.
• Based on RDF/XML syntax.
• Less commonly used today, but still in used by older sites.

Spec:

• RSS 1.0 Specification

Atom

Atom is a well-structured, modern alternative to RSS, standardized by the IETF.

• Designed to fix some shortcomings of RSS.
• Strong support for namespaces and extensibility.

Spec:

• RFC 4287 (IETF Atom Spec)

Podcast-Specific RSS Extensions

Podcast feeds rely on RSS 2.0 with custom tags and extensions to support rich metadata like episode duration, artwork, and transcripts.

Specs and Guidelines:

• Podcast RSS Tags (Podcast Standard)
• Spotify Podcast Delivery Specification
• Apple Podcast Requirements
• Podcast Index Namespace
• Google Podcasts RSS Guide
• Podlove Specifications

---

RSS Autodiscovery

Autodiscovery allows browsers and readers to detect feed URLs automatically from HTML pages.

Spec:

• RSS Autodiscovery Guide

JSON Feed

JSON Feed is a modern alternative to XML-based feeds using JSON, designed to be easier for developers to work with.

• Developer-friendly.
• Supports common feed features like items, authors, and attachments.

Spec:

• JSON Feed Version 1

WebSub (formerly PubSubHubbub)

WebSub is a real-time subscription protocol for delivering updates when content changes.

• Push-based delivery model.
• Useful for live or fast-changing content feeds.

Spec:

• W3C WebSub Recommendation

OPML

OPML (Outline Processor Markup Language) is commonly used to share collections of RSS feeds (e.g. exporting/importing your feed subscriptions).

• Not a feed format, but a way to organize them.
• Used by most RSS readers for import/export.

Spec:

• OPML.org

Feed Validators

Validate your feeds for correctness and compatibility using these tools:

• W3C Feed Validator
• Atom Validator

Summary

Standard	Format	Use Case
RSS 2.0	XML	General-purpose feeds
RSS 1.0	RDF	Metadata-rich, legacy
Atom	XML	Standardized alternative to RSS
Podcast RSS	XML	Audio/video podcasting
JSON Feed	JSON	Developer-friendly alternative
WebSub	N/A	Real-time feed updates
OPML	XML	Subscription lists
Autodiscovery	HTML	Feed detection on websites