Comment threads collapsed by default, so that initially only the top-level comments are visible. Then I could drill down into threads only if I am interested in continuing.

However, one of the best "features" of HN is its relative lack of features.

- Exchanging the position of the vote and the collapse buttons or just moving the collapse button the the leftmost spot.

- Also a way to filter out (to make invisible) comments based on when the comment matches a regex (or at least a direct string match)

Proper Markdown support for inline elements such as bold, _italic_, [link]() and `code` (and maybe ```fenced code blocks```). While having full GitHub Flavored Markdown would be nice, I think image, headers and tables and other block elements should stay turned off, because they disrupt the flow of the text

Larger vote and collapse buttons for mobile so you're not constantly tapping the wrong thing by accident.

I would very much love a "feature" to disappear: the silent rewriting of titles in submissions.

Just right now: "The Forgotten Lens" became "The Lens".

Some time ago, someone posted "How I Choose What to Read" (an essay on how he selects books) which became "I Choose What to Read" (must be an angry rant about main stream media shoving fake news into his face).

Unfortunately, the mods have already clarified that this "feature" is here to stay.

I call it commment thread bailout collapsing.

I’ll often have read ten deep into a long thread and have reached my fill of the discussion but it’s a but cumbersome to scroll back and find the parent to collapse the thread. I want to just bail out.

Hashtags / labels som that the content becomes curated.

Only sorting by upvotes / comments is too 1 dimensional for me, and it does not favours to the future readers of the site, nor to the goldmine content posted here.

Not a perfect solution, but the algolia search index is pretty good at finding topical articles that are most popular. If you don't use it already, it's the search bar at the very bottom of the front page.

Ability to only see new comments. Maybe kind of gray out previously read comments. On the main page tell you how many new comments there are.

History of recently viewed posts like Reddit, things can disappear from the front page fast.

Probably just web push notifications for when users directly reply to your comment.

This. Or just some way to keep track of a conversation without constantly refreshing

This is doable with hnrss if RSS is good enough:

https://hnrss.org/replies?id=devwastaken (replies to any of your comments)

https://hnrss.org/replies?id=19599229 (replies to a particular comment ID)

This exists, though it's a free third-party service.

http://www.hnreplies.com

An option to highlight comments that were added since I last read the thread. Often when I find one interesting, I start reading comments (and possibly replying) early and check back several times. It's annoying to have to go over everything again that was already there last time. Right now I have to search repeatedly for '2 hours ago', '1 hour ago' and 'minutes ago', or wait until the thread has cooled down to read all at once.

Decent styles and markup. I like the simple design, but:

- the font is too small. It's impossible to read on a mobile or tablet. Body font is set to 10pt; comments to 9pt. Just use the browser default size (1em ~= 16px)

- the markup is really bloated for what it does. The nested tables are unnecessary.

Bookmarklet to fix the font size on mobile: https://news.ycombinator.com/item?id=19468463

Agree about the markup, but the current font is perfect on small phones. Anything larger would have a line length with too few characters to be legible; and reader mode doesn’t work.

A kill file.

Automatic highlighting of not-yet-seen comments.

There is a "hide" button. Not sure if that's what you mean by "kill file."

A "kill file" was a feature popularized by Usenet news readers. It lets you save a list of terms that you're not interested in seeing. For example, you may never want to see articles or comments from a particular user or which contain a particular phrase.

I'd like to see downvotes only used when a comment doesn't add to the conversation, not when the comment gives a wrong answer. Some comments highlight a popular misconception which is useful to the conversation.

I think this is more a UX problem, where sites like Stack Overflow use downvotes to indicate that they disagree with the answer.

Maybe instead of a downvote button it should be a flag or -_- emoji. (edit: apparently HN removes emojis)

Ability for me to mark a user as "someone I'd like to meet". If they also mark me within 12 months, then we both get an automated email. If they don't, nothing happens.

It would probably need some anti-abuse mechanism, to prevent someone from just marking every single user.

Auto wrapping code quotes.

Ability to make links open in a new tab by default.

Middle click links? It's a good habit.

Perhaps NNTP service