Wall-Jump! Mod

Wall-Jump! is an amazing mod that gives your Minecraft player the ability to climb walls. On default, you can press and hold the LEFT SHIFT key after jumping onto a wall, in order to cling on to the wall. From there, you can perform many other stunts, and that includes climbing walls.

Wall Cling: Jump towards a wall and hold the wall jump key (LSHIFT). Then...

Wall Jump: While wall clinging, keep holding W and let go of LSHIFT to wall jump.

Double Jump: Optional mid-air jump that you can use to your advantage.

The video linked below gives you a demo on how you can cling and climb walls using this mod.

This is a Forge mod and download links are given below. Read the installation instructions carefully.