I've done both (chart and journal). Always on paper. Like others, writing helps get the thoughts out of my head. Or depressurizes a bit, lol. I SHOULD keep better track of things, because I have no sense of time. Someone did snoop and misinterpret something in notes section of chart one time, which made me hinky. For awhile, I continued to chart, but restricted so much in the notes section that it was rather pointless.

Then I picked up journalling again --get this-- in the midst of a big time paranoia attack(!!!) BUT. It was in code. Has been ever since. Although it is very complicated, I can write it very nearly as fast as regular writing. Reading it back... Not so much. (It's do-able, just doesn't lend itself to scanning, lol.)

Which....not too big a deal as I don't tend to reread. However, I did sometimes make little faces in the margin to help locate significant stuff.

I'm kind of paranoid of online. But that's just me.