From time to time I get questions about how to check differences between two Git commits or two branches, I will answer those questions in this post.

How to check differences between two branches:

Example:
you have a dev branch and a master branch. You develop in the dev branch and would like to know if you were to merge the dev changes to master, what will those changes be:
Please note the order of the branch this states differences that will be added to master from dev.

How to check differences between two commits:

Example:
When you do git log you will see your different commits over time, you need to check the differences between two commits.

commit eab54d0ec21a1d7e351fee4c67139ada740e7e6b
Author: John
Date: Wed Jul 8 22:18:05 2015 -0400

Add feature 2

commit b722f1650b9fb33e0990beec027c097526c61478
Author: John
Date: Wed Jul 8 22:31:18 2015 -0400

Add feature 1

// Remember the order the first argument is the point in time, and the second item is what is added to the first argument’s commit

How to check differences between the HEAD (current state/latest revision) and a previous commit:

Or you can specify the last commit or a number of commits:

// Last commit

//Last 2 commits

How to check what changed since yesterday or a specific date:

// OR a specific date

How to check all changes to a specific file:

How to check size differences between two trees

I found this one in stackoverflow and has been very useful:

Reference Source: http://stackoverflow.com/questions/10845051/git-show-total-file-size-difference-between-two-commits/10847242#10847242

“git cat-file -s will output the size in bytes of an object in git. git diff-tree can tell you the differences between one tree and another. Putting this together into a script called git-file-size-diff located somewhere on your PATH will give you the ability to call git file-size-diff . Putting this together we can try something like the following” – Stackoverflow

// Using it to check size differences between two branches:

// Using it to check size differences between the local master branch and the remote master branch, this is useful to know how much data will be downloaded when doing a ‘git pull’: