What is an IO file?
An .IO file is most often a BrickLink Studio LEGO Model. It is created by LEGO BrickLink, a platform for building digital LEGO creations. The .IO file contains 3D parts, colors, layout instructions, and model data. Other software programs also use the .IO extension. For example, draw.io uses it to store flowchart diagrams. Sometimes, .IO files act as web application configuration files or MHTML complete web page archives.
How to open IO files?
You can open a BrickLink Studio LEGO Model using the official BrickLink Studio software on Windows or macOS. If your .IO file is a flowchart diagram, you must open it with draw.io. Because an .IO file has multiple possible meanings, we recommend using viewer.online/io to identify the actual format of your file.
Software and tools
If you need to edit a 3D LEGO model, BrickLink Studio is the primary desktop tool. For web diagrams, draw.io works directly in your browser. Network engineers and developers might also see .IO files used as configuration logs in IO Ninja or web archives exported from services like resume.io.
Best practices and troubleshooting
Do not change the file extension manually to fix an opening error. This usually breaks the file structure. Instead, use a file inspection tool. viewer.online/io analyzes .IO files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
Summary
Because the standard BrickLink Studio LEGO Model .IO files use the known ZIP format, viewer.online/io can safely open and display them online, eliminating compatibility problems.