According to several sources like the Cambridge Dictionary, “although” and “though” have the same meaning. However, “although” is considered to be slightly more formal in style.
Google Ngram Viewer tells us that “though” is increasingly more commonly used, but “although” is holding its own. Of course, the Ngram Viewer does not tell us how those words are being used in a sentence, so other uses of “though” might be the reason for its popularity.
Hence, you should probably use “though” instead of “although” if it is important to avoid sounding formal (for example, in a blog post or personal communication) or if you want a modern, concise style, even in your formal writing. That said, if your personal preference is for “although” (as mine is), it is fine to use this term in your own work.
