Crystal Client
First up for the best Minecraft clients for PvP, we have Crystal. Although this one's more focused on the Factions game mode, it has pretty good mods and features for PvP as well. You can expect mods from the Crystal client for FPS boosting, PvP mods, HUD mods, macros, and even customization features like capes!
When it comes to downsides for the Crystal client it's that custom mods can't be added, and it's limited to older Minecraft versions. Even though there are the essential PvP mods here, compared to the rest of the clients here, I'd recommend you use the Crystal client if you're into Factions with a side of PvP!
LabyMod Client
Next up we have the LabyMod client, which is definitely one of the best Minecraft PvP clients because of how many mods and features it has. Some features and mods include FPS boost features like fast-world loading, PvP mods for seeing your combo or the enemies' hitboxes, and much more which you'll have to check out for yourself!
LabyMod also includes the option to download your custom add-ons and mods within the client. I personally use toggle-sprint to run in-game, and LabyMod does give me the chance to download an add-on for it. However, lots of players have complained that LabyMod is slow on low-end PCs, so you may want to increase your FPS if you're planning on using it!
Tecknix Client
If tons of mods and features confuse you, then Tecknix will be one of the best Minecraft clients for you. Tecknix has HUD, server mods, and mechanical mods like toggle-sprint and removing enemy name tags for PvP! The latest version of Tecknix also supports Forge, meaning you can download and install custom mods.
Although Tecknix is a great Minecraft client, there isn't support for lots of game versions. Right now, Tecknix only supports Minecraft Forge 1.8.9! There aren't many options to get a big FPS boost, though it's very well optimized, so you shouldn't be having any problems with it.
BatMod Client
Having a natural feel for hitting an enemy in PvP gameplay is a must when it comes to the best Minecraft clients. For that, I'll recommend the BatMod client because of its hit registration on enemies! There are a ton of customization options alongside HUD and PvP mods too, so you won't be missing out on them.
Unfortunately, you won't be able to use custom Forge mods on the BatMod client. So if you're a fan of the best HUD Minecraft mods, know that you won't be able to install them in BatMod. You may also experience FPS drops, but that depends on which mods and features you use for this Minecraft client, simply because of how many there are!
Soar Client
Some clients here may look old-school, and the Soar client will please your eyes because of its beautiful GUI and HUD mods and features. Besides that, the Soar client also has lots of PvP mods like showing hitboxes, changing the crosshair, hit-delay fixes, and even changing the hit color!
There are also customization options where you can equip yourself with a cape. But much like the other clients we saw here, the Soar client is limited to fewer Minecraft versions, and you won't be able to add custom mods. Though I'd say this is one of the best Minecraft clients out there because I combined it with the best Minecraft PvP key binds, and it worked flawlessly.
Salwyrr Client
One of the best Minecraft clients I've used for low-end PCs is Salwyrr simply because of how smooth it is and how much it can increase your FPS. It comes packed with a lot of PvP mods and features, and the best part is that Salwyrr is available even for newer Minecraft versions!
Although this might sound like the ideal PvP client for Minecraft out there, there are still some flaws as some players find the HUD mods and elements a bit ugly. If you don't mind the looks at all and only care for mods and mechanics, then Salwyrr might just become one of the best Minecraft clients for you, even if you set the best PvP settings!
Cosmic Client
There are many cool things like private Minecraft servers when it comes to the Cosmic client, but speaking of PvP there are some nifty mods you'll find useful. Some of the features in the Comsic client are chunk borders, crosshair changes, information and armor HUD, keystrokes, and more!
When using the Cosmic client, some players have noted that there are FPS drops and lag when playing on other servers besides the Cosmic one like Hypixel. I personally got an increase in FPS, so this issue most likely appears in low-end PCs.
Feather Client
When it comes to some of the most optimized clients for PvP in Minecraft, Feather is definitely one of them including support for various game versions, PvP mods, FPS boosting, and even includes cosmetics! Since it's based on Forge, you can also add custom mods for the various Minecraft versions the Feather client supports.
Unlike how you may get confused with the tons of mods the previous clients had, Feather has a simple solution where you can set your favorite built-in mods for faster access. Comparing FPS performance optimization with previous clients as well, Feather does run better. And in my opinion, it's very close to the Salwyrr client with the FPS boosting!
Lunar Client
Lunar is one of the most popular Minecraft PvP clients because there are constant updates to it alongside the best PvP mods like Hypixel mods, the Replay mod, and much more! Other features like cosmetics are also included, albeit you'd be more interested in the fact that the Lunar client can double your FPS!
Because of how popular it is, the Lunar client is also constantly updated to the latest Minecraft versions. However, Lunar doesn't support custom mods. Some players have reported having a bad PvP hit registration on some servers, but that really depends on your PC.
Badlion Client
Finally, the title for the best Minecraft client has to go to Badlion. This is mostly due to how much it can increase FPS, even on the worst PCs out there! No matter the potato PC, the Badlion client has tons of features that can increase your FPS including an excellent selection of PvP mods.
Sadly, Badlion doesn't support custom mods compared to some of the other best Minecraft clients we saw for PvP previously. But considering how much Badlion can increase the FPS anywhere, you probably won't be needing to install the best mods for FPS boosting!
And this wraps it up for the best clients for PvP. Minecraft itself does run perfectly, but these clients can help you in subtle ways to defeat your enemies more easily. But I'd say you get a client that supports mods so you can also download the best Minecraft modpacks too!