What is a RELS file?
A .RELS file is an Open Office XML Relationships File. It uses the XML format. Microsoft created this system for the Office Open XML standard. When you save a file in a modern Office format like .DOCX, .XLSX, or .PPTX, the software builds a compressed archive. Inside this archive, an `_rels` folder contains the .RELS files. These files store the internal connections between different parts of the document, such as images, text, and structural styles.
How to open RELS files?
Users often find .RELS files when they extract a Microsoft Office document like a standard .ZIP archive. viewer.online/rels analyzes .RELS files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. If your .RELS has multiple possible meanings, we recommend using viewer.online/rels to identify the actual format of your file.
Software and tools
Since they contain standard text, you can open .RELS files with developer tools like Visual Studio Code or Notepad++. You can also manage the parent documents directly using Microsoft Office.
Best practices and troubleshooting
Do not delete or modify .RELS files manually. If you remove these files, the parent document will break and fail to open. If you need to share the raw code, you can use convert.guru to convert the .RELS file to standard .XML or .TXT formats.
Summary
Because .RELS files use the known XML format, viewer.online/rels can safely open and display them online, eliminating compatibility problems.