How do you change sort order in a thread on mobile vs. desktop?

Changing the sort order on Reddit works slightly differently depending on whether you are using the desktop website, the official iOS app, or the official Android app, though the core logic is the same across all platforms: sort controls exist both at the feed level (which posts you see) and at the comment level within an individual thread. On the desktop website, when you are inside a community or viewing your home feed, the sort options (Hot, New, Top, Rising, Controversial, Best) appear as a row of tabs or a dropdown near the top of the post listing. Clicking any of them immediately reorders the feed. Inside a specific post, the comment sort options — New, Best, Top, Old, Controversial, and Q&A — appear directly above the first comment, typically as a small dropdown or button. Clicking it gives you the full list of comment sort modes. On the official mobile app (iOS and Android), feed-level sorting is typically accessed by tapping a small label or arrow near the top of the community page — it often shows the current sort (e.g., "Hot Posts") and tapping it opens a sheet where you can select a different option. Inside a post, comment sorting is done by tapping the sort indicator above the comments section, which opens a similar selection sheet. According to r/NewToReddit guidance, mobile app users can also set a default comment sort in the app's settings by navigating to the avatar, then Settings, then the Advanced section, where a "Default Comment Sort" preference is available. This is a mobile-exclusive setting not replicated on the desktop site. On desktop, you must change comment sort manually each time you enter a thread unless you are using old.reddit.com, which remembers some preferences via URL parameters.