Or always available as a user script: https://arantius.com/misc/greasemonkey/hacker-news-comment-collapse.user.js https://arantius.com/misc/greasemonkey/hacker

Or always available as a user script: https://arantius.com/misc/greasemonkey/hacker-news-comment-collapse.user.js https://arantius.com/misc/greasemonkey/hacker-news-comment-c... Also collapses by default threads below depth two.