.RL file extension

Q: Is .RL an XML file?

Often, yes. RFC 4826 defines an XML “Resource Lists” format and explicitly lists .rl as its file extension, with the registered media type application/resource-lists+xml. However, some programs also use .RL as an app-specific data file extension.

Q: What program should I use to open a .RL file?

If it’s an RFC 4826 resource list, any text/XML editor can open it because it’s XML. If it’s not XML, you usually need the application that created it (FileInfo documents an .RL variant created by R.viewer).

Q: Can I convert a .RL file by renaming it to .XML?

Renaming doesn’t convert the file. If the .RL file is already XML, renaming may help some programs recognize it, but it doesn’t change the underlying format; if it’s not XML, renaming won’t make it readable.

Q: What MIME type is associated with .RL for the standards-based format?

RFC 4826 registers application/resource-lists+xml and lists “.rl” as the file extension for that media type.

To open .RL files on Windows, right-click the .RL file → Open with → choose a text/XML editor (e.g., Notepad) to see if it is XML (look for “<?xml” or “<resource-lists”).

To open a .RL file, first determine whether it is an RFC 4826 XML Resource List (you can open it in a text/XML editor) or an app-specific RL data file (open it with the app that created it, such as R.viewer). If you’re unsure, try opening it as plain text to identify whether it contains XML.

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Last updated: June 11, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page

Format fit: whether the “what is this file?” description matches common real-world use of the extension, including category, typical MIME types, and aliases.
Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
Sources and further reading: whether external links point to vendors, standards bodies, or other primary references where possible; we avoid inventing details we cannot ground.
Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .RL files

Use these platform-specific instructions to open .RL files safely.

Windows

Right-click the .RL file → Open with → choose a text/XML editor (e.g., Notepad) to see if it is XML (look for “<?xml” or “<resource-lists”).
If it is an RFC 4826 resource list, keep using your editor/XML tool; if it appears to be app-specific data, open it with the program that created it (FileInfo lists R.viewer as a creator for one .RL variant).
If Windows prompts for an app and you don’t know the source, do not rename the extension—inspect as text first to avoid opening it in the wrong program.

Full Windows guide

Mac

Control-click the .RL file → Open With → choose a plain-text editor (e.g., TextEdit in plain text mode) to check whether it contains XML.
If it contains RFC 4826 XML, you can view/edit it as XML; if it does not look like XML, use the originating application (some .RL files are app-specific).
If you only need to read it, viewing as text is the safest first step.

Full Mac guide

Linux

Open the file in a text editor (or run: xdg-open file.rl or open it with a GUI editor) to check whether it is an XML Resource List.
If it is XML, handle it as application/resource-lists+xml (your desktop may map this via shared-mime-info); otherwise, open it with the program that created it, if known.
If file associations are wrong, update your desktop MIME associations (shared-mime-info describes how MIME/extension mapping works).

Full Linux guide

iOS

In Files, try Quick Look; if it doesn’t preview well, share/open it in a plain-text editor app to check whether it is XML. For non-XML .RL files, you’ll typically need the original desktop application.

Full iOS guide

Android

Open it with a text editor app to see whether it contains XML. If it’s not XML (or looks proprietary), transfer it to a desktop system with the originating application.

Full Android guide

Security notes

RFC 4826 .RL files are XML; while they are typically just data, XML parsers can still be exposed to maliciously crafted input (e.g., extremely large or complex XML). Prefer opening unknown .RL files in a simple text viewer first.
Be cautious with .RL files that are not XML (garbled/binary-looking): they may be proprietary data meant for a specific application, and opening them in the wrong tool can trigger plugin/import code paths you didn’t intend to use.
If an .RL file references external resources (common in list-style formats), treat embedded URIs/paths as untrusted until you verify the source and intent of the file.

If you did not expect this file

This extension is usually plain data, text, or structured content—not a program by itself. The practical risk is social engineering (a scam attachment or misleading filename). For trusted senders you rarely need heavy-handed antivirus wording; use these tools when you want an extra check on unexpected downloads.

Avast

Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.

Norton

Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

Can't open this file?

These are the most common causes and fixes when .RL files fail to open.

Common reasons

The .RL file won’t open or you’re prompted to choose an app
The file opens as garbled text
Linux desktop doesn’t recognize .RL / wrong file association

Fix steps

Open the .RL file in a plain-text editor first to determine whether it is XML (RFC 4826 Resource Lists).
If it is XML, continue using an XML-capable editor/viewer; if it is not XML, identify the creating app (FileInfo notes an .RL variant created by R.viewer) and open it there.

OS-specific troubleshooting

What is a .RL file?

Per RFC 4826, a common meaning of .RL is an XML format for representing “resource lists,” registered with the media type application/resource-lists+xml and the file extension .rl. In practice, this means many .RL files are readable text (XML) and can be inspected with any text editor. Separately, some software uses .RL as a proprietary “data file” extension (for example, FileInfo describes .RL files created by R.viewer that store lists of files/folders).

Background

In standards-based contexts, “.rl” is the designated file extension for XML Resource Lists defined by RFC 4826. The RFC also registers the corresponding MIME type application/resource-lists+xml, which desktop systems can use to associate files with suitable applications.

Because RFC 4826 Resource Lists are XML, they are often easiest to handle like other XML documents: open in a text editor to read or edit, or in an XML-aware editor to validate and format. On Linux and other desktop environments, file associations can be driven by shared-mime-info rules that map extensions to MIME types.

At the same time, the .RL extension is not exclusively reserved for the RFC format. FileInfo documents .RL as a file created by R.viewer that stores lists of files and folders, meaning some .RL files are best opened with that specific application rather than treated as XML. When you receive an .RL file, inspecting the contents (as text) and knowing its source is usually the fastest way to choose the right tool.

Common MIME types: application/resource-lists+xml

Common .RL issues

The .RL file won’t open or you’re prompted to choose an app

This often happens because .RL can refer to different formats, or your system has no app associated with application/resource-lists+xml (RFC 4826).

Open the .RL file in a plain-text editor first to determine whether it is XML (RFC 4826 Resource Lists).
If it is XML, continue using an XML-capable editor/viewer; if it is not XML, identify the creating app (FileInfo notes an .RL variant created by R.viewer) and open it there.

The file opens as garbled text

If a .RL file is not an RFC 4826 XML Resource List, viewing it as text may show unreadable characters because it is a proprietary or binary format.

Confirm whether the file begins with XML text (e.g., “<?xml”). If not, treat it as application-specific data.
Ask the sender which program created the file and open it with that program (for one known variant, FileInfo lists R.viewer).

Linux desktop doesn’t recognize .RL / wrong file association

Desktop environments typically rely on shared MIME databases to map extensions to MIME types; the mapping may be missing or overridden.

Verify the file is an RFC 4826 resource list (XML) before changing associations.
Review or update your MIME associations using your desktop settings; shared-mime-info explains how MIME and filename globs (extensions) are defined and used.

FAQ

Is .RL an XML file?