How hashtags work on Bluesky
A hashtag on Bluesky is a link to a search and a signal to feeds. Used well it puts a post in front of people who chose to see that topic. Used badly it is noise.
What a hashtag does on Bluesky
Three things. It becomes a link: tapping it opens a search for that tag. It becomes a signal: custom feeds built with tools like Skyfeed and Graze can include posts carrying a tag, so the right tag puts a post in a feed that people subscribed to. And it becomes findable: Bluesky search matches tags exactly, so a person searching the tag finds the post.
What it does not do is ask any algorithm to show the post more widely. On the Following feed a tag changes nothing. On Discover a tag is one signal among many, and a weak one.
Hashtags in threads
Search and feeds find a thread by its first post. A closing line of tags on the last post of a thread reaches nobody. Put the tag line on the first post, after the hook, and keep that first post short enough that the hook and the tags both fit. The Planner does this for you when it splits a long post into a thread: the tag line moves to the first post on its own.
How many, and case
Tags are matched without regard to case, so #BookSky and #booksky are the same tag; capitalise for readability if you like. On the number: in Updrift's own figures, posts carrying one or two tags on the post's real topic beat an account's usual post more often than posts with none, and posts with three or more rarely do. Tags cost characters and attention; spend them on the topic, not on reach.
Hashtags and custom feeds
This is the part that matters most on Bluesky. Many communities live in a custom feed built around a tag or a set of tags: an art feed that picks up #art and #illustration, a book feed, a feed for a game. Getting into that feed is a matter of using the tag the feed reads, posting the kind of thing the feed's followers want, and, sometimes, being on the feed builder's allow list. The starter packs guide covers the other route in.
Measuring tags against your usual post
The only way to know which tags work for your account is to measure your posts with each tag against your own median post. Updrift's hashtag table does this on every plan, Free included: each tag you have used, how the posts carrying it did against your usual (as a percentage), how many posts that is, and whether the figure is rising or falling. A tag with too few posts behind it says so rather than guessing.
Tags busy in your topic
Alongside your own tags, it helps to know which tags are busy right now among the posts in your topic. On a paid plan the composer suggests a few: your own tags that beat your usual, tags busy in recent posts on your topics, and tags others often save alongside the ones you chose.
Mistakes to stop making
- A wall of tags at the end of every post. It reads as noise and rarely helps.
- Tags on the last post of a thread. Nobody finds them there.
- Tags for reach rather than topic. A tag on a topic the post is not about brings the wrong people, briefly.
- Never checking. A tag that worked in spring may be dead by autumn as feeds change.
Questions
Do hashtags work on Bluesky?
Yes, differently from other networks. A hashtag is a link to a search for that tag and a signal custom feeds read. It does not by itself push a post to more people; it makes the post findable by people and feeds looking for that topic.
How many hashtags should I use?
One to three, on the topics the post is actually about. Posts with three or more tags rarely beat an account's usual in Updrift's figures; one or two often do.
Should hashtags go in a thread's first post?
Yes. Bluesky search and feeds find a thread by its first post, so the tag line belongs there, not at the end of the thread.
See your own figures, free.
Followers by the hour, the posts that landed, your best hours and how your hashtags do. One account, no card, for good.
The Planner, the Inbox and the full What works report come with a paid plan, 7 days free. See the plans.