I use HackMD, which supports Markdown and various other plain-text formats, including LaTeX, Mermaid, GraphViz, etc: https://hackmd.io/c/tutorials/%2Fs%2Ffeatu

I use HackMD, which supports Markdown and various other plain-text formats, including LaTeX, Mermaid, GraphViz, etc: https://hackmd.io/c/tutorials/%2Fs%2Ffeatures https://hackmd.io/c/tutorials/%2Fs%2Ffeatures For your use case, it saves files immediately as you type them. It's also collaborative and can sync to GitHub. As an extra bonus, optional Vim and Emacs keybindings are built right in.