EncodingMaster is an excellent software tool which even boasts BATCH-PROCESSING! I am using it to convert entire folders of numerous UTF-16 text files (exported as complex HTML from FileMaker Pro 7) into UTF-8 files.
FMPro7 can export "text field contents" (as opposed to records) ONLY as UTF-16, which normally prevents users from using the client-level FMPro 7 as a broadly-compatible Web-site generator or host unless they upgrade to the FMPro Server versions ($1K+). EncodingMaster fixes this UTF-16 problem.

Note that including a HTML meta-tag specifying a "charset" DOES NOT by itself make a Web page readable correctly by a client browser. The invisible code "under" the HTML text may still contain conflicting Windows, Mac, or language-specific code that the browser (or Google's indexing and cached files!) can't display correctly. It takes an industrial-strength text-utility like EncodingMaster to correct the problem -- hopefully by batch-processing your whole Web-site.

Suggestions: The author might consider an "Advanced" setting in EncodingMaster to permit users to convert their ORIGINAL text files (instead of the admittedly safer "Save a Copy" default). In my case. all my original data resides in the FMPro database, so the exported HTML text files are easily replaced. Another option would be a user-definable target folder/path for saving converted files. Also useful would be for the program to retain the user's favorite conversion-settings as named, reloadable configuration files.