What is the RSS file format?
Files with the .rss extension are rich site summary files - XML-format documents utilized by websites to distribute content through an RSS feed. An .rss file typically comprises news headlines, blog entries, and other web-related content in a structured text-based format that feed readers and browsers with built-in RSS support can parse and display automatically.
The dominant standard is RSS 2.0, finalized in 2002. An RSS 2.0 document wraps a <channel> element (metadata: title, link, description, pubDate) around a series of <item> entries, each with a URL, description, and unique <guid>. The <enclosure> element attaches audio or video files per item - making RSS the backbone of podcast distribution.
RSS feeds are typically served dynamically by web servers returning application/rss+xml, not stored as static .rss files on disk. Feed readers such as Mozilla Thunderbird, QuiteRSS, and Feedly all support the format. The competing Atom standard (RFC 4287, 2005) addresses some RSS ambiguities but RSS 2.0 remains the more widely deployed format.
Security & safety
RISK: LOWAn RSS file is a passive XML document - it cannot execute code. The content within feed items (description/content:encoded) may contain HTML, which could theoretically have XSS payloads if rendered by a vulnerable RSS reader that executes untrusted HTML. Well-maintained readers sanitize HTML content. The <enclosure> element links to external media files that carry their own risk if executed.
Format details
in a nutshell- Rockwell Logix 500 SLC-5 Application File - Allen Bradley/Rockwell Automation uses .rss for PLC programming project files - an industrial automation context, entirely unrelated to web feeds.
- ReliaSoft BlockSim Reliability Simulation File - ReliaSoft's BlockSim reliability software uses .rss for simulation data files.
Programs that open RSS files
Windows3 apps
Mozilla Thunderbird
Open-source File > Subscribe to this Feed, paste the feed URL or drag the .rss file. Thunderbird handles RSS feeds natively alongside email. 
Feedly (web)
Freemium Add a feed by URL in Feedly's web app; Feedly does not directly import .rss files but fetches from the feed URL.
Notepad++ (text/XML view)
Open-source Open the .rss file to view and edit raw XML; useful for debugging malformed feeds. 
macOS3 apps
NetNewsWire
Open-source Free, open-source RSS/Atom reader for macOS and iOS. Add a feed by URL under File > New Feed. 
Linux2 apps
Mozilla Thunderbird
Open-source Native Linux build; subscribe to RSS feeds under File > Subscribe to this Feed. 
Android2 apps
Technical details
deep spec| File type | XML-based web feed document |
| Encoding | Text, XML (UTF-8 most common; declared in XML header) |
| MIME type | application/rss+xml |
| XML root element | <rss version="2.0"> containing <channel> (RSS 2.0); <rdf:RDF> root for RSS 1.0 |
| Specification | RSS 2.0, published 2002-09-09; copyright held by RSS Advisory Board |
| Required channel elements | <title>, <link>, and <description> are mandatory per the RSS 2.0 spec |
| Podcast support | <enclosure> element carries audio/video URL, byte length, and MIME type per item |
| Item identifier | <guid> element; isPermaLink attribute signals whether it resolves to a URL |
| Update frequency hint | <ttl> element specifies time-to-live in minutes |
| Typical size | 10 KB - 100 KB for a feed with 20 recent items; up to 500 KB for large archives |
| Compression | Stored uncompressed; commonly gzip-compressed in HTTP transport |
| Competing standard | Atom (RFC 4287, 2005) - IETF-standardized alternative; both widely supported by feed readers |
| Earlier versions | RSS 0.91/0.92 (Netscape, 1999-2000); RSS 1.0 (RDF-based, 2000) |
| Associated OS | Windows, macOS, Linux, Android, iOS, web (cross-platform) |
| Released | March 1999 (RSS 0.9 by Netscape) |
| Latest version | RSS 2.0 (2002-09-09, Harvard specification) |
| Open standard | Yes · royalty-free |
| Specification | www.rssboard.org |
RSS conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about RSS files.
