RELS File

What are RELS files and how to open them

Are you having problems opening a RELS file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your RELS files.

What is a RELS file?

RELS files have multiple uses, and Open Office XML Relationships is one of them. Read more about the other uses further down the page.

Open Office XML Relationships

Files that contain the .rels file extension are relationship files. These files contain information about how the parts of different Microsoft Office documents fit together. This information is also referred to as relationship parts.

RELS files serve as markers for the documents that they pertain to. They allow the various Microsoft Office applications to utilize the information in one file to be used in another file.

The RELS file format is only compatible with the more recent versions of the Microsoft Office applications, which support Open Office XML documents. The RELS files are saved in the directory of the Open Office XML document.

How to open RELS files

We have identified two RELS openers that are compatible with this specific type of RELS file.

Programs that open Open Office XML Relationships files

Last updated: January 25, 2025

All known file formats using extension .RELS

While Open Office XML Relationships is a popular type of RELS-file, we know of 2 different uses of the .RELS file extension. Different software may use files with the same extension for different types of data.

3D Manufacturing Format Relationships

We know that one RELS format is 3D Manufacturing Format Relationships. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

While we have not verified the apps ourselves yet, our users have suggested ten different RELS openers which you will find listed below.

Various apps that use files with this extension

These apps are known to open certain types of RELS files. Remember, different programs may use RELS files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about RELS file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.