Roblox sprint script

Players hold Left Shift to run faster, and phone players get a button for it.

Where it goes

1In the Explorer, open StarterPlayer, hover over StarterCharacterScripts, press + and choose LocalScript.
2Delete what's in it, paste this in and press Play.
3Hold Left Shift to run. Try a phone in Studio's Device view to see the button.

Sprint · a LocalScript in StarterPlayer > StarterCharacterScripts

1-- From forja.us/tools/roblox-scripts/sprint2-- Hold Left Shift, or the button on a phone, to run.3local ContextActionService = game:GetService("ContextActionService")45local WALK_SPEED = 166local SPRINT_SPEED = 2878local character = script.Parent9local humanoid = character:WaitForChild("Humanoid")1011local function onSprint(_, inputState)12	if inputState == Enum.UserInputState.Begin then13		humanoid.WalkSpeed = SPRINT_SPEED14	else15		humanoid.WalkSpeed = WALK_SPEED16	end17	return Enum.ContextActionResult.Pass18end1920ContextActionService:BindAction("Sprint", onSprint, true, Enum.KeyCode.LeftShift)21ContextActionService:SetTitle("Sprint", "Run")

How it works

It's a LocalScript in the character, so it runs on the player's own device and starts again each time they respawn.
BindAction listens for the key, and its true asks Roblox to make the button on touch screens.
WalkSpeed is how fast the character moves: 16 is Roblox's normal speed.

Make it yours

Faster or slower: Change SPRINT_SPEED. Past about 40, players are hard to control.
Another key: Replace Enum.KeyCode.LeftShift, for example with Enum.KeyCode.Q.