End Portal framed are constructed with 12 end portal blocks and 12 eyes of ender. However an end portal can not be crafted on survival vanilla minecraft, it has to be found inside a stronghold.
Stepping into an activated end portal immediately opens up a loading screen, and transports the player to the End – this leaves no time to back out, unlike the nether portal while in Survival mode. Upon entering the End, a 5×5 horizontal platform of obsidian is spawned centered at block coordinates (100, 48, 0), and the player is placed on top of it.
The black portal blocks emit a light level of 15, which is as powerful as glowstone and is the brightest light level there is. Through the use of the /setblock and /fill commands, you can place these portal blocks anywhere, and they will still function as if they were a complete portal and you will be able to teleport to the end using this method.
To Find a Stronghold:
Use an Eye of Ender to find the Stronghold in your world. To do this, you will need to select the Eye of Ender in your hotbar and then throw it into the air to see which direction it goes.
You will see the Eye of Ender float up into the air, hover, and then drop to the ground. This is the direction that you need to go. If the Eye of Ender did not break, you can pick it up and throw it again.
Continue to throw the Eye of Ender into the air until it hovers over one spot. This is the location of your Stronghold. Start digging straight down at this location.
Once you find the Stronghold, you will need to travel through the hallways searching for the End Portal. Chances are, you will not find the End Portal directly where you dig down, so it may take some time and patience to find the End Portal.
Once the portal is found place the correct amount of eyes of ender into each empty portal block.