What are the BLEND1 files?

BLEND1 files are automatically generated backup files by Blender, designed to store previous versions of your .blend projects, enabling recovery in case of data loss or unwanted changes.

Understanding BLEND1 Files

A BLEND1 file serves as an automatic backup copy created by Blender, the popular open-source 3D creation suite. When you save a .blend project, Blender intelligently generates a .blend1 file, which is essentially the state of your project before the current save. This mechanism is crucial for safeguarding your work against accidental overwrites, software crashes, or undesirable modifications.

Key Characteristics:

Automatic Generation: Blender creates these files automatically upon saving your main .blend file.
Version History: They represent the immediate prior saved version of your project, acting as a quick undo button for your entire file.
Purpose: Primarily used for recovering an older, stable version of a .blend file.
Renaming Capability: A .blend1 file can be easily converted back into a standard .blend file by simply renaming its extension from .blend1 to .blend.

How to Use BLEND1 Files for Recovery

If your primary .blend file becomes corrupted, you accidentally save over important work, or you simply need to revert to a previous state, BLEND1 files are your immediate solution. Here's how to utilize them:

Locate the File: Navigate to the directory where your main .blend file is saved. You will typically find files like yourproject.blend, yourproject.blend1, yourproject.blend2, and so on.
Identify the Desired Version: The BLEND1 file is the most recent backup (the last saved version before the current one). BLEND2 would be the one before that, and so forth, depending on your Blender autosave settings.
Rename the File: Right-click on the .blend1 file (e.g., yourproject.blend1) and select "Rename." Change the file extension from .blend1 to .blend (e.g., yourproject_recovered.blend). It's highly recommended to give it a new name to avoid overwriting your current working .blend file.
Open in Blender: You can now open the newly renamed .blend file in Blender as you would any other project file.

Why BLEND1 Files are Important

These backup files are an indispensable feature for any Blender user, providing a safety net that can prevent significant data loss and save hours of work.

Crash Recovery: If Blender crashes, the .blend1 file often contains the last successfully saved version, minimizing lost progress.
Undoing Major Changes: For irreversible changes or complex operations, reverting to a .blend1 backup can be quicker and more reliable than trying to undo multiple steps within the software.
Experimentation: They allow you to experiment freely with your project, knowing you can always go back to a stable version if something goes wrong.

Blender File Types at a Glance

File Extension	Description	Primary Function
`.blend`	Blender 3D Data File	Main project file containing all 3D scene data.
`.blend1`	Blender Backup File	Automatically created backup of the previous `.blend` save.
`.blend2`, etc.	Older Blender Backup Files	Further historical backups (number corresponds to age).

For more comprehensive information on Blender's file formats and their preservation, you can explore detailed resources such as the Library of Congress's digital formats descriptions.