Use word wrap instead
Are you looking for a way to reduce the font because the text doesn’t fit in the dialog window?
If so, most likely you are trying to fix the problem in the wrong way. I recommend you to learn the word wrap feature in Translator++.
Make the most of the game engine’s capabilities in Translator++
If you still want to reduce the text size for some reasons, you can use the command from the game engine that you are working on. The text you type in Translator++ is actually what you see in the respective engine editor. So, you can use the tags and all (and for that reasons you see those bunch of weird tags in the translatable text, right?). For example, in RPG Makers you use \} to reduce the font size, and \{ to increase. You can use that in Translator++ too!
Each game engine has their own way of increasing or decreasing the font. Visit the respective website or forum discussion to learn more about how to resize fonts. For example, a quick google search on how to resize font in RPG Maker MV give us the solution: https://forums.rpgmakerweb.com/index.php?threads/decrease-text-size.137415/
Be creative
The general idea is that Translator++ is able to do what is possible on the game engine with the existing framework of the game in question. But sometimes you come across text that can’t be clipped with word wrap or can’t be reduced in size. Like for example the text on the menu or on the item description and so on. This is most likely because the game developer didn’t expect the text to be translated into another language and left only a little extra room for longer words. For example, in Japanese, a word that translates to Experience Point takes only 3 digits full width character: 経験値. Meanwhile, it requires a 16 bit half-width character in English, more than two times the original length! Most Japanese developer didn’t see that coming.
When this happens, be a more creative. Game translators have long since overcome this solution by replacing translations with shorter words. Maybe the substitute words do not a hundred percent match with the original meaning. It is OK! trust me, it works!
You can even invent your own term or naming. Why not, You’re the translator. It is your privilege!
For example in the Tales series, the term “Arte” comes from the word “術技” which when translated literally means “movement technique”. The translators was creative, so now we are all familiar with this new word.
Or you can make abbreviations. That’s why you often see Exp instead of Experience Point, or SP instead of Skill Points and so on. Over the years this technique has proven to be very effective, to the point that now you find it strange to see the word “Experience Point” instead of “Exp” in your game menu, And Japanese game developers are starting to use this term too.