Each Minecraft version plays differently: combat, available blocks and mobs, plugins and modpacks. Here is how 1.8 and 1.21 compare, and which servers accept them.
Criterion
Minecraft 1.8
Minecraft 1.21
Combat
No attack cooldown: fast clicking and combos
Attack cooldown, shield and mace
Content
Old: no shield, elytra or recent blocks
Tricky Trials: trial chambers, the Breeze, the mace, new copper blocks
Plugins and mods
Very mature PvP and minigame plugins
Up-to-date plugins (Paper), last series of the old numbering
Performance
Very light, even on a small PC
Demanding, but well optimised by Paper
Choose 1.8 if…
… you want competitive PvP, minigames or BedWars, with "old school" combat.
Choose 1.21 if…
… you want a recent, stable version accepted by most up-to-date servers.
Top Minecraft 1.8 servers
#1LodgeCraft1.8 - 1.21 · LodgeCraft, serveur Minecraft Survie FR : progression, économie, quêtes, guildes, donjons et contenu personnalisé.3votes this month
#1Aera1.21.11-26.2 · 🎃 Halloween sur AeraSRP ! Survie semi-RP crossplay Java & Bedrock : figurines et clés d'Halloween, métiers, pets, météorites et concours de récolte.163votes this month
#2PixelSMP1.21.11 · 🌍 PixelSMP | Serveur Minecraft Survie avec une communauté active, des métiers, des rangs évolutifs, une économie, des événements et des récompenses exclusives.140votes this month
#3Cobblemon : Frontier1.21.1 · Serveur Cobblemon RP Town, rejoins une ville et creer la tienne et developpe ton empire10votes this month
What is the difference between Minecraft 1.8 and 1.21?
1.8 : combat : no attack cooldown: fast clicking and combos ; content : old: no shield, elytra or recent blocks ; plugins and mods : very mature PvP and minigame plugins ; performance : very light, even on a small PC. 1.21 : combat : attack cooldown, shield and mace ; content : tricky Trials: trial chambers, the Breeze, the mace, new copper blocks ; plugins and mods : up-to-date plugins (Paper), last series of the old numbering ; performance : demanding, but well optimised by Paper.
Should I play 1.8 or 1.21?
Choose 1.8 if you want competitive PvP, minigames or BedWars, with "old school" combat. Choose 1.21 if you want a recent, stable version accepted by most up-to-date servers.
Can I join a 1.8 server with 1.21?
Only if the server accepts several versions (ViaVersion plugin). 1 listed server(s) accept both 1.8 and 1.21.