You might find it very hesitating to find the difference between two large text files for their difference. There are many tools will compare two text files for you while you wait. These tools will be useful for Web Designers, Bloggers, Students, and you.
If you don’t want to install an application just to compare two text file, then you can use an online tool that does this work. Yeah, I’m talking about the website Comparemyfiles.com
CompareMyFiles.com
This tools lets you just what you want to do, just upload the text file or file you want to compra ena click on the Compare button, and all the left will be done by CompareMyfile.com
These are the other tools (Installation required) that let you compare the difference between two text files.
WinMerge
WinMerge is differencing and merging tool. WinMerge can compare both folders and files, presenting differences in a visual text format that is easy to understand and handle.
This tool is only available for Windows operating system.
This tool is highly useful for determining what has changed between project versions, text, code etc, and then merging changes between the compared file. WinMerge can be used as an external differencing/merging tool or as a standalone application.
Beyond Compare
Beyond Compare allows you to quickly and easily compare your files and folders. By using simple, powerful commands you can focus on the differences you’re interested in and ignore those you’re not. You can then merge the changes, synchronize your files, and generate reports for your records.
You can compare entire drives and folders at high speed, checking just sizes and modified times. Or, thoroughly verify every file with byte-by-byte comparisons. FTP sites and zip files are integrated seamlessly, so you can update your website with the touch of a button. The below screenshot will show you about how it compares a local folder and an FTP site. Differences are highlighted in color.  The default color for newer files is red and is configurable.