One of the best features on Mastodon and other Fedi platforms is that you can follow hashtags. This makes posts using that hashtag appear in your main timeline even if you aren’t following the person who made it, helping you discover interesting and relevant stuff.
You can find out how to follow hashtags in the guide, and most hashtags people use are just straightforward topic names such as #Gardening or #Cooking or #BoardGames etc. Basically, for any topic just stick # at the beginning of the word or phrase and capitalise the first letters of each word.
However, there are also popular hashtags which may not be immediately obvious. Here is an attempt to list some of them:
| #3GoodThings | People listing three good things that happened to them that day, or which they appreciate that day. |
| #AcademicChatter | Academics discussing academia |
| #ActuallyAutistic | Discussion by and for autistic members of the Fediverse |
| #ArtForSale | Art for sale from independent artists |
| #AskFedi | General queries on any topic, asking for advice or help |
| #Asstodon | Donkeys |
| #BandcampFriday | Independent musicians on days when musicians selling via Bandcamp get to keep all the money from their sales |
| #BlackMastodon & #BlackFedi | Discussion by and for black members of the Fediverse |
| #Bloomscrolling | Flowers |
| #Bookstodon | Books |
| #Breadposting | Baking and breadmaking |
| #Catstodon | Cats |
| #Caturday | Cats on Saturdays |
| #ClamFacts | Clam trivia |
| #Defaidodon | Sheep |
| #DogsOfMastodon | Dogs |
| #DOScember | MS-DOS computers, games and software during December |
| #FairTradeMusicFriday | Independent musicians who are using alternatives to Bandcamp including Faircamp and Mirlo |
| #FediAdmin | Running a Fediverse server |
| #FediArt | Posting art that you’ve made |
| #FediBlock | Recommending blocks of servers that are doing bad things, usually blocks by admins |
| #FediBlockMeta | Discussing the general topic of blocking on the Fediverse without actually suggesting blocks |
| #FediDogs | Dogs |
| #FediGiftShop | Art for sale from independent artists |
| #FediTips | Tips on using Mastodon and the wider Fediverse |
| #FensterFreitag | Views from windows or views of windows on Fridays |
| #FernFriday | Ferns on Fridays |
| #Florespondence | Flowers |
| #FollowFriday | Recommending accounts to follow on Fridays |
| #FootpathFriday | Hiking and walking trails on Fridays |
| #FossilFriday | Fossils on Fridays |
| #FridayThrillerClub | Watching a thriller together on Fridays |
| #FungiFriday | Fungi on Fridays |
| #GetFediHired | People looking for work, people offering work |
| #HashtagGames | Humorous posts based on wordplay challenges |
| #HawkPants | Hawks that look like they’re wearing trousers |
| #Histodons | History |
| #Inktober | Drawing with ink during October |
| #InsectSaturday | Insects on Saturdays |
| #Introduction | Brief introduction post about yourself |
| #JMusicFriday | Japanese music on Fridays, sometimes with a specific theme each week |
| #JoinIn | Everyday life of people looking for conversation, especially at Christmas |
| #JukeboxFridayNight | Music on Fridays, often with a specific theme each week |
| #KPopMonday | K-Pop music on Mondays |
| #LazySunday | Relaxing stuff on Sundays |
| #LichenSubscribe | Lichens |
| #MacroMonday | Macro photography on Mondays |
| #MagicInTheMundane | Beauty in everyday objects or situations |
| #MakanApaToday | South-East Asian food |
| #Marchintosh | Old Macintosh computers during March |
| #MastoAdmin | Running a Mastodon server |
| #MastoArt | Posting art that you’ve made |
| #MondayActionMovie | Watching an action movie together on Mondays |
| #MondayMotivation | Helping people keep going on Mondays |
| #MonDog | Dogs on Mondays |
| #MonochromeMonday | Black and white photography on Mondays |
| #Monsterdon | Watching monster movies together |
| #MosaicMonday | Photos of mosaics on Mondays |
| #Mosstodon | Moss |
| #MountainMonday | Photos of mountains on Mondays |
| #MovieClub | Watching films together, new film every two weeks |
| #Mushtodon | Mushrooms and fungi |
| #MusicWomenWednesday | Musical women on Wednesdays |
| #NowPlaying & #NP | Music |
| #NowReading | Books |
| #PhDLife & #PhDone | Discussion by PhD students and recent ex-students |
| #SaturdayScenery | Landscape photography on Saturdays |
| #SepTandy | Tandy computers during September |
| #ShrimpSunday | Shrimps and prawns on Sundays |
| #SilentSunday | Calm photos on Sundays |
| #SolarpunkSunday | Solarpunk topics on Sundays |
| #Sporespondence | Mushrooms and fungi |
| #Sportsball | Sport |
| #StandingStoneSunday | Photos and drawings of ancient megaliths on Sundays |
| #TextureTuesday | Photography emphasising texture on Tuesdays |
| #ThickTrunkTuesday | Trees on Tuesdays |
| #ThrowbackThursday | Photos and/or memories from the past on Thursdays |
| #ThursdayFiveList | Lists of five songs on Thursdays, with a specific theme each week |
| #TilingTuesday | Tiling in art, crafts and maths on Tuesdays |
| #TimelineCleanse | Anything that brings pure innocent joy |
| #TinyBalancingSheep | Photos of sheep where they look like they’re balancing on fences and posts |
| #TongueOutTuesday | Animals sticking their tongues out on Tuesdays |
| #TrainTrackTuesday | Photographs of railway tracks on Tuesdays |
| #TuneTuesday | Songs on Tuesdays, with a specific theme each week |
| #VendrediLecture | French-language books on Fridays |
| #VintageAd | Retro advertisements |
| #WaterfallWednesday | Waterfalls on Wednesdays |
| #WhiskersWednesday | Cats on Wednesdays |
| #WildlifeWednesday | Wildlife photography on Wednesdays |
| #Wrensday | Wrens on Wednesdays |
If you see irrelevant, offensive or spam posts on these or any other hashtags, you can report it by clicking ⋯ on the post and then Report.