No sync servers severely break most multihacks, in particular XP hacks. Since hacking is easier on sync server, no sync doesn't appear to be getting a lot of attention. Most hacks just say "some stuff might no work on no sync". Which stuff? Well after testing on a lot of different servers I'm gonna try to create a list of hacks that work in no sync so that some good Samaritan will make the worlds first no sync hack pack.

Safe No Sync Hacks

Gold
No recoil
No spread
Fast ROF?
Infinite Stamina
Faster crouching (just running speed or you will be kicked)
ESP (500 range is best)
Long Melee range (only vs cars, trees, buildings, zombies)
Instant Disconnect, Home, and respawn
No zombie/wildlife aggro

Things that break on No Sync (atleast)

Infinite XP (The reason for this thread, breaks all skills)
Speedhacks (Not ever worth it)
Infinite Electricity (Tested: it's only client side)
Custom skins (Tested: it's only client side)
Big Backpack
Infinite Health
No Infection
No Hunger
No Thirst
No Bleed
No Broken Legs
Instant Axe
One-shot Zombies
Super gas can
Reputation Editing
Hacked Items
High Zoom
No Zombie Damage
High Jump


Please let me know if I missed anything else that can be safely used on No Sync servers, or if there is anything else that completely breaks them.