Blender file signature
Magic number at the start of the file · BLENDER
A Blender project starts with the ASCII magic BLENDER, then one byte for the pointer size and one for endianness, then a three-digit version such as 403 for Blender 4.3.
What this magic number means
A magic number is a short, fixed run of bytes at a known position that tells a program what a file really is, no matter what the filename says. If a file starts with the bytes 42 4C 45 4E 44 45 52 (the text BLENDER), it is a Blender file.
Formats that use the 42 4C 45 4E signature
These file types in our database carry this signature:
How to check a file's signature
You can read the first bytes of any file yourself. The magic bytes are shown in hex, the same way this page lists them.
Linux & macOS
- xxd -l 16 example.blend
- hexdump -C -n 16 example.blend
- file example.blend
Windows (PowerShell)
- Format-Hex -Path example.blend -Count 16
Python
- open("example.blend","rb").read(7).hex()
In your browser
- Drop the file into the WhatFileType identifier, which reads the signature without uploading it.
Frequently asked questions
What is the Blender file signature?
Blender files start with the hex bytes 42 4C 45 4E 44 45 52 (BLENDER in ASCII). This magic number identifies the format regardless of the file's name or extension.
How do I check a file's magic number?
Open the file in a hex editor, or run a command such as xxd -l 16 example.blend on Linux or macOS, or Format-Hex -Path example.blend -Count 16 in Windows PowerShell, and read the first bytes.
Can a file fake the Blender signature?
Renaming a file does not change its bytes, so the extension can lie but the signature usually cannot. A genuine Blender file has these exact bytes; a file with the wrong bytes is not really Blender, whatever its name says.