It's great when there are just few good and reliable software tools that you wish to use, but when market is flowed with inexpensive tools with poor documentation and customer support, you might find it time consuming to get and evaluate a good software program. I'd like to represent some soft of buying guide for file and folder compare tools.

There are a number of features you should pay attention to. You will need to carefully pay attention to supported file formats, supported methods of comparison and merging, methods of folder comparison, reporting functions, and finally pricing.

I'm sure you'd like to start with pricing, and it is reasonable in this case. I won't pay for utilities priced above 100$, these tools are designed to professionals in some particular business and usually lack some really popular features that you might find in other tools. Getting and using freeware tool, might be a solution, if you just want to try with file or folder compare tool, but remember to check all other functions, make sure you are investing your time in a proper way.

Pay attention to supported compare methods and reporting functions. What compare method do you need? Depends on your task. If your main task is to compare folders, then make sure the program has a folder synchronization function, which allows you not only compare two folders, but copy files in both directions. It also might be useful a function called 'folder snapshot', when you can compare one snapshot against another one without comparing actual files, it is very useful if files you need to compare are too large.

Methods of comparison, such as 'Three-way', 'Char-by-char', 'Word-by-word,' 'By-keyword'. The first two methods will be useful for software developers, end users should pay attention to word-by-word and by-keywords compare methods. If you need compare html files then by-keywords feature will help you much. But if you are a software developer, then you will find very nice to have a syntax rules highlighting in your compare program.

If you main task is text auditing, e.g. approving and rejecting changes, then you should pay attention to merge function of compare tool. I'm sure you will need 'Auto Merging' and conflict reconciling functions to process with routine jobs. By the way, pay attention to automation abilities. Good compare tool must have a command line interface which will enable to integrate it with some third-party software, for instance version control software.

What about file compare formats? Which one do you need? It is good idea to have a list of formats which you are dealing with, I'm sure you will start with task to compare Microsoft office Word and Excel files, probably plain text files and source codes of some programs, web-page documents. Consider this list carefully and try to add all formats you have dealt with last week. So that is a requirement list for your compare tool. Actually, there is no much choice, but you will be able to do a side-by-side comparison at your own before investing in new tool.