Note: You will only be able to change your skin if you have migrated your premium account already. So to change your skin, you will first need to migrate your account to Mojang.
Uploading a player skin (Minecraft: Java Edition)
To create your own skin, download the classic or slim-armed reference skin below and edit it to your liking. Then sign in to your Minecraft profile at minecraft.net/profile and upload your skin.
Outer skin layer
As of Minecraft version 1.8, skins can have a second layer on each body part. For information on creating a custom skin, visit the Minecraft Wiki.
Only the inner part of a dual-layer skin will be visible if you use it while playing a Minecraft edition older than version 1.8.
If you've not uploaded a custom skin, you'll have either the classic "Steve" skin or the newer "Alex" skin, which features slimmer arms. Which default skin that you get is randomly based on your account ID and cannot be changed. This skin is also shown when you don't have a connection to the skin servers.
You can create your own skin based on either model using the reference templates below:
Slim-armed skins are only fully supported in version 1.8 and higher; if you have a slim-armed skin selected in a version prior, you will see black pixels on the arms.
Skins in Bedrock versions of Minecraft
There are both free and purchasable skin packs that can be obtained in the Minecraft Marketplace. After downloading these skins, you can equip them through the profile menu. Go to “Edit Character” and you will be able to equip skins that you have downloaded through the Classic Skins tab. In the Character Creator tab you are also able to make your own skin, choosing both the body and style features of the skin, along with the colors. You are also able to have up to 5 saved skins that you can easily switch between.
Additionally, for the Windows 10 and mobile versions of Minecraft you can upload your own custom skin by going to Profile > Classic Skins > Owned > Import. However, custom uploaded skins will not roam to other devices.
Why does the website say that I have to pay to change my skin?
This message is displayed if you are not currently logged into an account which contains a paid copy of the Java version of Minecraft. If you can only play the demo, visit this article.
Why don't I see my skin in multiplayer?
If you are unable to change your skin or do not see your skin in multiplayer, visit help.minecraft.net to see if the skins server is temporarily down. If you see the default skin in-game, first check server status, then refresh by logging out and back in. If everyone's skins show as the default, the server may be running in offline mode.
I uploaded a new skin; why did my skin not change?
Skin changes in Minecraft version 1.7.9 and later should happen immediately. If you are playing version 1.7.8 or an earlier version, skin changes may take up to an hour to be applied. If you are playing version 1.3 or earlier, skin changes will not be reflected in-game.
Why are there black lines on my skin's arms?
You'll see black lines on your arms in versions 1.8 and later if your profile has a classic model selected, but you've uploaded a slim-armed skin. To fix this, visit Minecraft.net/profile and upload the correct skin type for the model you've selected.
You'll also see this issue if you've uploaded a slim-armed skin prior to them being implemented in the game (versions 1.7.9 or earlier). To fix this, visit Minecraft.net/profile and upload a classic skin.