I am trying something similar: I made game as a standalone HTML file with a feature that allows users to edit text and save as a new local version. Works on my phone (Android with Brave) but not on iOS with Safari.

I keep this bookmark in Chrome which lets me open an editor in a tab and Chrome maintains the state of the textarea even through reboots as long as you don't close the tab:

data:text/html,<html><head><title>Notepad</title><style>html,body{margin:0;padding:0;}textarea{padding:10px;font-family:Courier;font-size:16px;height:100%;width:100%;border:none;outline:none;}</style></head><body><textarea style="height:100%;width:100%;font-size:16px;padding:10px;"></textarea><script>document.getElementsByTagName('textarea')[0].focus()</script></body></html>

You can get rid of the JS by setting the autofocus[1] attribute to the textarea.

[1] https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/...

Thank you, I'm going to try this.

Thanks, I trimmed it down to this:

  data:text/html,<title>Notepad</title><textarea autofocus spellcheck=0 style="position:fixed;inset:0;padding:1em;border:0;font:monospace">