WinMerge, Beyond Compare, ExamDiff and Altova Diffdog are some popular utilities that help you visually compare differences in two files but a problem with these software is that they work only on the desktop.
Since there are no online file comparison services available yet, we can use our favorite Google Docs to locate differences between two text files or files that contain programming source code.
Here are the step involved for comparing two files with Google Docs:
Step 1. Create a new document in Google Docs and paste the contents of the first text file into this document. Save.
Step 2. Open your second text file in notepad and copy its content to the clipboard. Now open the Google Document created in Step 1 and overwrite everything with content from the clipboard. Save.
Step 3. Go to the Revision tab of Google Docs, select the two file versions and click "Compare Checked". You should see the differences highlighted on the next screen as shown below.
The highlighting may not be as good as the desktop counterparts but still handy. And this Google Docs file comparison trick will work best in situations when you have to compare two text files that contain only minor variations.