Reddit's share button produces links that are roughly three times longer than they need to be, and one of the parameters it adds is worth keeping in a specific case. That exception is the only complicated part.
What the share button gives you
https://www.reddit.com/r/example/comments/1a2b3c/some_post_title/?utm_source=share&utm_medium=web2x&context=3
/r/example/comments/1a2b3c/ identifies the post. The title slug after it is human-readable decoration and can be dropped without breaking anything.
utm_source=share and utm_medium=web2x record that the link came from the share button on the web interface. These are ordinary campaign tags of the sort described in UTM parameters explained, and Reddit is using them to measure its own share flows.
share_id appears on newer share links and identifies the specific share.
rdt shows up in some contexts as an additional tracking value.
The exception: context
context=3 is not tracking. On a link to a specific comment, it tells Reddit to show three levels of parent comments above the one you linked to.
That is often the entire point of sharing a comment. Without the context parameter, the comment appears on its own, and a reply that only makes sense as a reply becomes incomprehensible.
So: on a link to a post, context does nothing and can go. On a link to a comment, think about whether the thread above it matters. This is the same class of distinction as YouTube's timestamp or Instagram's carousel index, and it is why blindly cutting at the question mark is a bad habit.
Cleaning by hand
For a post, everything after the post ID can go, including the title slug:
https://www.reddit.com/r/example/comments/1a2b3c/some_post_title/?utm_source=share&utm_medium=web2x
https://www.reddit.com/r/example/comments/1a2b3c/
For a comment permalink, keep the comment ID in the path and decide about context deliberately.
Reddit-specific quirks worth knowing
old.reddit.com and www.reddit.com serve the same content through different interfaces. Swapping the subdomain changes which interface the recipient gets, which is a preference rather than a cleaning question, though plenty of people share old. links on purpose.
Reddit also wraps some outbound links, and image and video links often point at i.redd.it or v.redd.it rather than the post itself. Sharing the media URL rather than the post link strips the comments, which is usually not what people intend.
Why I clean these more than most
Reddit links get pasted into other Reddit threads constantly, and a URL ending in utm_source=share&utm_medium=web2x inside a comment is a small tell that somebody used the share button rather than copying the address. It is a trivial thing and nobody is judging anyone for it.
What actually pushed me to bother was length. Reddit links are long to begin with, and the share parameters push them past the point where they stay readable in a chat app. The clean version fits on one line. The share version wraps twice and ends in a string of nonsense.
The other reason, and this one is more substantive: Reddit users are unusually attentive to this stuff. If you are sharing links into technical or privacy-minded communities, arriving with a clean URL is a small signal that you know what you are doing.
Doing it in one step
Paste the URL into the links cleaner and it strips the share tracking while leaving the post path intact.
Related reading
UTM parameters explained for the utm_source=share pattern.
The URL tracking parameter glossary for everything else.
Frequently asked questions
Can I delete the title slug from a Reddit URL?
Yes. The post ID is what resolves the link. The slug is decoration.
What does context=3 do?
It shows three levels of parent comments above a linked comment. Keep it when the thread matters.
Is rdt_cid the same as these?
No. rdt_cid is Reddit's advertising click identifier and appears on links from promoted posts, not on shares.
Does cleaning affect the post's karma or ranking?
No. Votes and rankings are unrelated to URL parameters.
Should I share old.reddit.com links?
That is a preference about which interface the recipient sees, not a cleaning decision.