What are differences between AssemblyVersion, AssemblyFileVersion and AssemblyInformationalVersion?


Where other assemblies that reference your assembly will look. If this number changes, other assemblies must update their references to your assembly! Only update this version if it breaks backward compatibility. The AssemblyVersion is required.

I use the format: major.minor (and major for very stable codebases). This would result in:

[assembly: AssemblyVersion("1.3")]

If you’re following SemVer strictly then this means you only update when the major changes, so 1.0, 2.0, 3.0, etc.


Used for deployment (like setup programs). You can increase this number for every deployment. Use it to mark assemblies that have the same AssemblyVersion but are generated from different builds and/or code.

In Windows, it can be viewed in the file properties.

The AssemblyFileVersion is optional. If not given, the AssemblyVersion is used.

I use the format: major.minor.patch.build, where I follow SemVer for the first three parts and use the buildnumber of the buildserver for the last part (0 for local build).
This would result in:

[assembly: AssemblyFileVersion("")]

Be aware that System.Version names these parts as major.minor.build.revision!


The Product version of the assembly. This is the version you would use when talking to customers or for display on your website. This version can be a string, like ‘1.0 Release Candidate‘.

The AssemblyInformationalVersion is optional. If not given, the AssemblyFileVersion is used.

I use the format: major.minor[.patch] [revision as string]. This would result in:

[assembly: AssemblyInformationalVersion("1.3 RC1")]

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