MKV2MP4 not including subs when converted

[Acker-Z]

I don't have that much knowledge of converting/encoding videos. I have a couple of mkv files which I would like to convert to mp4.

Upon searching, I found that https://www.videohelp.com/software/MkvToMp4 works best without any quality loss. But the problem is that when I converted it to MP4, It didn't included the subtitles along with it so MP4 was pretty much raw.
Is it some settings about subtitles that I will have to change so It includes subs instead of raw conversion? Here's the settings of subtitles (Also, what's "codepage for non-unicode"? It's a bunch of letters+numbers but Idk what It's about or which one is best)

I tried to convert into both (MP4 & M4a) but both didn't had any subtitles.



If anyone can tell me best settings for high quality mkvtomp4 (with subs & without subs) that will be awesome. Or If there is a better way than this software?

[Case]

when I converted it to MP4, It didn't included the subtitles along with it

How do you know? Did MediaInfo say that there is no subtitle track in the output?
Does your player of choice even support internal subtitles (of the transferred kind) in MP4 files?
Could it be that the subtitles are off by default, and you have to select/activate them?

Is it some settings about subtitles that I will have to change so It includes subs?

What kind of subtitles are inside the MKV? Images (VobSub) / SRT / SSA / ASS / … ? MediaInfo can tell you this.
Supported subtitle format are: srt, ass, ssa, ttxt.

what's "codepage for non-unicode"? It's a bunch of letters+numbers but Idk what It's about or which one is best)

You are seeing a list of standards, mostly abbreviations. The “cp” at the beginning of some, is short for “codepage”. The standards describe things like character no. 233 in one set is “é”, and character no. 233 in a different set is “й”.
Unicode (Universal Coded Character Set) is a standard for text documents, in particular the character encoding of most glyphs from most scripts and languages (somewhat like “all languages/scripts combined”). One such standard is UTF-8, which is probably implied here, when the developer talks of Unicode.
Non-unicode refers to text encoding that is not defined by the Unicode Consortium (almost everything that is not UTF-…), but defined by some other party.
The codepages are largely language based: English subtitles will often have a Western encoding (e.g. cp1252). Cyrillic, Greek, Chinese will have different code pages, as cp1252 doesn’t contain the needed characters for these other languages.
Inside MKV and MP4 it should be UTF-8 Unicode. However, when it is not UTF-8, the software has no way of knowing which codepage it should apply, thus asking the user to make a choice, or set a default.

I tried to convert into both (MP4 & M4a) but both didn't had any subtitles.

M4A is intended for audio files.