I'm not really worried about speaking voice given time and practice, but... I really want to sing beautifully 

Yet it feels very hard or almost impossible to take a certain quality out of my voice that sounds unfeminine. It's very subtle but it is there.

It's not even an issue of range and like, falsetto vs. chest voice... it's some quirk going on with the timbre.

Does anyone have any thoughts on fixing that? It is really hard to find info geared toward this kind of thing. I don't really understand why but a passable singing voice seems so much harder than a passable speaking voice  my bf tells me my singing voice passes but I really feel unsure and if it does I don't think it's pretty. When I hear cis girls singing beautifully I just get kind of sad and I feel like I can't reach that.

I think it could be because we probably all practise the speaking voice a lot more than the singing voice.

My speaking voice is more feminine than my singing one as well. Like you said, there's always a certain quality in my singing voice that sounds unfeminine... but I think it can't really be helped. I know it passes fine, because I like to sing with online pals who don't know I'm trans (just separately and not simultaneously though since there's too much lag)... but if you know I'm trans, there are plenty of obvious, telling flaws. I don't have the range of most cis-girls either, so I tend to stick to songs that aren't so high.

I do regularly (though not super frequently) record my singing and listen to it, like how people practise their voices, so I think I am somewhat better at singing than I would have been otherwise. I put quite a few of the recordings on my blog. Maybe it is a matter of practising enough, though if so, I don't think I'll be practising enough to really sing beautifully.

apple pie, thank you for the reply.

I listened to your clips and they did sound good. Better than most could do. 

In your one clip you struggled with D5. That is also around where my voice becomes tense and one-toned. I also noticed that you had a similar problem to one I have in that your voice sounds better singing some songs than others.

I guess we both have to practice more... I hope that a natural-sounding singing voice is something that is obtainable with practice. I am not able to practice much atm because I'm in the closet at home but do hope to get more in in the future. 

Unrelated but I thought your accent was interesting (for the japanese songs). English is not your first language I'm guessing, right? It sounded similar to Assoluta's accent. 

(also I would post some samples of my own but I cannot practice right now)

Thanks pretty! Yes indeed, I sound better singing some songs and sound really bad in another ones, even if they are well within my range. I believe that partly, it is because of a song's average pitch. I seem to have two or three optimal average pitches, and if I sing songs with average pitches which aren't close to those, then they sound bad. So transposing (up or down) sometimes fixes it.

I actually feel it's more acceptable to practise singing than to practise speaking while in the closet. I used to do it back in high school (when I was 16) in front of classmates (and once in front of the whole school), when my speaking voice had fully cracked but my singing voice still sounded like a girl. Everyone seemed to think it's really cool for a guy (whose voice has already cracked) to be able to sing like a girl. Soon after, though, I lost that singing voice as well... my present one was trained from scratch

I definitely feel that my singing voice has improved with practice when I listen to recordings from e.g. two years ago, so I think practice definitely helps, though the progress has been veeery slow. It's hard, too, because there don't seem to be many publicly available guides as to how people like us can sing better. The singing guides on YouTube or wherever are all geared towards non-trans people, and they don't suit my voice well. So I have been just experimenting on my own. Without realizing it until much later, I ended up going against what would be conventional wisdom and turned my chest voice into a girl voice (same for speaking). So even though I now always sing in a (trans) girl voice, I still have the same voice break as males at around E4 which I have to negotiate when singing (and talking), and I often mess it up. I want to take singing lessons but I am unsure whether singing instructors would be able to train a trans girl's voice like mine.

You're right that English isn't my first language. And there aren't any English-language recordings at all... not because I avoided English songs but because I barely know any! But probably not quite the same as Assoluta. The other three languages I regularly use are all Asian ones, being an ethnic Asian who grew up in Asia (though I'm now living in an English-speaking country)

I'm also kinda bummed that I have to start all over again in terms of singing, and that my voice will probably not be as good as others.
But then again, there's a lot of genetic girls that also have this problem, so I don't worry.