RELS File Extension
Open Office XML Relationships Format
- File Type rels
- Developer Microsoft
- Popularity
- Application Microsoft PowerPoint
- Category Document Files
- Format XML
What is a RELS file?
The RELS file extension is linked to Open Office XML Relationships Format and belongs to the Document Files category, which includes 969 files.
The Open Office XML Relationships Format (RELS), created by Microsoft, is one of file format they developed, and they also built 242 programs to support them.
RELS files are supported by Windows, Mac OS and Linux. When working with RELS files, you can rely on 8 programs, including Microsoft PowerPoint, Sublime Text and PSPad.
Programs that support RELS files
How to open a RELS file?
If you can’t open a RELS file, it is usually because the necessary software is missing. To resolve the issue, select the right program from the list for your operating system. Then go to the official website of the developer, download the software, and install it.
The most popular programs for working with RELS files are Microsoft PowerPoint, Sublime Text and PSPad. To install the latest version of Microsoft PowerPoint on your computer, visit the Microsoft website where you can download the version available for all operating systems.
Following installation, RELS files should be automatically opened with Microsoft PowerPoint.
Set Microsoft PowerPoint as your default RELS viewer
Changing the default program in Windows
- Right-click on your RELS file, then choose the "Open with" option and select "Choose another application" from the available options;
- From the list of applications in the pop-up window, find and select Microsoft PowerPoint as your desired application;
- Check the "Always use this app" checkbox, and then click "OK" to set your chosen app as the default for opening RELS files.
Set default app to open files on Mac
- Right-click or Control + left-click on the desired RELS file to open a menu of available actions;
- Select "Open in application" and click "Other";
- Look at the bottom of the window, where you will see the "Enable" menu. "Recommended Programs" will be selected as the default option;
- Within this menu select "All Programs" and navigate to Microsoft PowerPoint. Check the box next to "Always open in app" to make sure it’s the default option.
How to edit a RELS file?
To edit RELS files, you need to install specialized software that allows you not only to open but also to modify document files. Online RELS editors usually provide fewer features than software created specifically for Open Office XML Relationships Format.
Best RELS editors in 2026
Taking into account the provided details, we have prepared a list of RELS editors that match your needs.
| RELS Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| PSPad | Jan Fiala | Windows | 4.7 out of 5 (41 review) |
| Notepad++ | Notepad++ Team | Windows | 4.6 out of 5 (37 reviews) |
| Sublime Text | Sublime HQ Pty | Windows, Mac OS, Linux | 4.6 out of 5 (39 reviews) |
| Atom | - | Windows, Mac OS, Linux | 4.1 out of 5 (36 reviews) |
Solving Common RELS File Challenges
When issues arise with RELS files, they can generally be fixed with small software tweaks. Use the troubleshooting tips below to help resolve them.
What are the warning signs that my RELS file may be corrupted?
Corrupted RELS document files may have one or more of the following symptoms:
- Error messages appear during the course of working with the file;
- Poor performance when editing a file in Sublime Text;
- Attempts to open the file result in errors or failed results;
- Unexplained increase in RELS file size;
- The file causes Microsoft PowerPoint or other programs to hang or crash during operation;
Why does Microsoft PowerPoint crash?
Microsoft PowerPoint crashes can be caused by outdated software. Keep your Microsoft products up to date by installing the latest updates.
A simple restart of your computer can often fix many common problems, which is why it is the recommended first step before making any adjustments to your software settings.
How to repair a corrupted RELS file?
Use a data recovery program to open the damaged RELS file and from the menu choose "Repair" function to start the repair process. Please be patient while the recovery process completes, which will automatically restore the damaged document files.