If overflow: auto is set, the autoscroll in Log doesn't always work

[boris-gu]

The bug

If I set overflow: auto or overflow-y: auto, the Log does not start scrolling automatically right away. To enable automatic scrolling, I need to manually scroll it first or switch the parent TabbedContent.

In the video, I demonstrate autoscroll in two scenarios: correct and incorrect.

2025-11-21.16-03-20.mp4

[github-actions]

We found the following entry in the FAQ which you may find helpful:

• Why do some key combinations never make it to my app?

Feel free to close this issue if you found an answer in the FAQ. Otherwise, please give us a little time to review.

This project is developed and maintained by Will McGugan. Consider sponsoring Will's work on this project (and others).

This is an automated reply, generated by FAQtory

[TomJGooding]

MRE:

from textual.app import App, ComposeResult
from textual.widgets import Log


class LogApp(App):
    CSS = """
    Log {
        overflow: auto;
        height: 10;
    }
    """

    def compose(self) -> ComposeResult:
        yield Log(id="log1")
        yield Log(id="log2")

    def on_ready(self) -> None:
        lines = [f"Line {n}" for n in range(20)]
        for line in lines:
            self.query_one("#log1", Log).write_line(line)
            self.query_one("#log2", Log).write(line + "\n")


if __name__ == "__main__":
    app = LogApp()
    app.run()