96 Exit Guide
This guide aims to show you all the secret exits in Super Mario World that are required in order to reach all 96 exits, which is this game's equivalent of 100%. This guide assumes you are already familiar with Super Mario World and have beaten it at least once. Therefore, the guide will not cover any levels that have no secret exits. While it may deter some from reading further, I do recommend for your first playthrough that you don't bother with getting every exit. Discovering stuff by yourself and going at your own pace makes the first playthrough far more enjoyable, and some of the secret levels can be incredibly frustrating for a new player. I hope you understand my reasoning.
Without any further ado, let's proceed.
Navigation
Donut Plains
Since there are no secrets in Yoshi's Island, it only makes sense to begin with Donut Plains.
Donut Plains 1
In order to find the secret exit, you need to use the Cape and fly up to the key and keyhole. The fastest way to get one is jumping on the first Super Koopa in the level and grabbing the Feather.
You can also use the Green Blocks near the normal exit once you unlock them, but since you likely don't have them unlocked, it makes sense to instead use the Cape to fly. If you've never done proper flight in SMW before, it might take time to figure out how to properly Cape Pump, but it's pretty easy to learn.
Fly above the green pipe that blocks the key and keyhole, and you'll make it through. Now grab the key and put it in the keyhole. You'll unlock the path to Donut Secret 1.
Donut Plains 2
Reaching the key requires going through a specific pipe in the level. It can be found right after the green block. It's the one above Mario in the screenshot below.
Going through it will lead you to a shortcut/secret path. In order to reach the key, you have to get through a small hole in the ceiling that will lead you to the key and keyhole. There's 3 ways to reach it.
The first way is to use a Cape. You can utilize spinflying (holding the spinjump button after reaching max speed/P-speed) to either fly up through the hole, or to hit the highest out of the 4 blocks in the room to release a vine. You can also spin into the block after jumping up the other blocks to release it.
The second way is to utilize the blue shell at the end of the room. Spinjump to break the blocks above the shell, then grab the shell and kick it upwards to also hit the highest block with the vine.
The third and final way is to utilize Yoshi. Make him eat the blue shell and press/hold the jump button to fly up through the hole.
After reaching the key, simply insert it into the keyhole. You'll unlock the path to Green Switch Palace.
Donut Ghost House
The secret exit on this one requires the Cape. Reaching it is simple. You have to go a bit to the right to have enough space for a run up to achieve P-speed. Then fly to the left and land on the ceiling platform.
Then just keep running to the right until you reach the end. Inside the blocks are 1-Ups which you can go ahead and grab if you want.
Donut Secret 1
The key for the keyhole is in a question mark block that's blocked by a few other blocks. They require a P-switch to be turned into coins. The P-switch is located not far from the key and keyhole.
I personally recommend killing every fish in the way between the P-switch and keyhole, and then carrying the P-switch near the keyhole. This will make traversing easier, and you won't be pressured by time. The fish do not respawn, so clearing the way is a viable option. If you're fast and capable enough, you can go ahead and press the P-switch right away and make your way to the key.
Once you have the P-switch, simply activate it and get the key from the question mark block and insert it into the keyhole. You'll unlock the path to Donut Secret House.
Donut Secret House
The secret exit is located near the end of the level. It's a hidden blue door above the normal blue door used to exit the level (the one surrounded by coins). In order to reach it, you have 2 options.
The first option is to fly up to the door with a Cape. Get a run up near the P-switch's location (to the far left of the room) and fly up to the alcove with the door. You can fly up there with the P-switch to save time.
The second option is to utilize the hidden vine next to the alcove. Activate the P-switch and hit the middle block above the door pictured below to release the vine. Then climb it quickly and make your way to the hidden blue door.
Once you enter the blue door, you'll be put into a boss fight against a Big Boo. To defeat it, you must use the blocks that make up the floor of the arena and throw them upwards at it. Do so 3 times, and you win.
After the boss fight ends, you'll unlock the path to the first Star World warp point. Completing the level normally with the other blue door unlocks the path to Donut Secret 2, which doesn't contain any secret exits.
Vanilla Dome
Vanilla Dome 1
Getting to the secret exit requires the red blocks to be active. The switch can be found by using the secret exit of Vanilla Dome 2. As far as I'm aware, there is no real method to get there with spinflying. Simply hit the block above the red blocks, climb the vine, and insert the key. You'll unlock the path to Vanilla Secret 1.
Vanilla Dome 2
To get to this secret exit, you'll have to go up a certain fork in the road and hit the P-switch. You can find the fork by getting to this particular block.
Once you're there, go up, and then left, until you find the P-switch. Grab it and put it next to the wall of blocks that blocks your path.
After the P-switch is activated, go through the coins and go to the left tunnel next to the one used to drop down to the water earlier.
The key will be on the ground. I recommend killing the fish once again to clear the path, but that is optional. Insert the key into the keyhole below and you'll unlock the path to Red Switch Palace.
Vanilla Secret 1
The secret is located in a pipe to the left of the level. To find it, make your way to the segment with the trampoline and Koopa Paratroopas.
You can utilize the trampoline to jump up from the blue blocks, but assuming you followed the guide from the beginning up till this point, you probably won't have it unlocked. The second method is to get a run up from the floor that Mario is standing on in the screenshot above, and flying to the pipe. Simply hold the jump button and the left direction once you gain P-speed, and you'll make it to the pipe.
Go through the pipe, complete the level with the secret exit, and you'll unlock the path to the second Star World warp point. Completing the level normally unlocks the path to a pipe that leads to Vanilla Secret 2 and 3, Vanilla Fortress, and Butter Bridge 1 and 2. All of these don't have any secret exits.
Twin Bridges
Cheese Bridge Area
The secret exit is located behind the normal exit.
You have 2 options to reach it, both of which require a Cape. You can utilize Yoshi to float to under the normal exit, jumping up from him to behind it. Alternatively, you can take flight from anywhere in the level, and maintain it until you reach the last 2 saws in the level. Then do a dive bomb under the normal exit and fly back up.
Completing the level with the secret exit unlocks the path to Soda Lake, which doesn't have any secret exits. Complete Soda Lake and you'll unlock the path to the third Star World warp point.
Forest of Illusion
Forest of Illusion 1
In order to reach the secret exit, you have to first make it to the block with the P-balloon. Pick it up, and instead of going to the right, go left under the wooden logs.
Keep going until you reach the keyhole and a block, which contains the key. Wait until your P-balloon power expires, pick up the key and put it in the keyhole. You'll unlock the secret path to Forest Ghost House.
Forest of Illusion 2
Near the end of the level, you'll find a yellow block and what looks like a wall blocking a path. The wall isn't actually blocking the path, and you can go through it to find the secret.
Insert the key and you'll unlock the path to Blue Switch Palace.
Forest of Illusion 3
Near the Splittin' Chuck in the level, there is a tall green pipe. Enter it.
You'll find yourself in the location of the secret. You will need to be powered up and do a spinjump on top of the blocks to be able to access the key and keyhole.
Insert the key and you'll unlock the path to #5 Roy's Castle. Completing the level normally will unlock the regular path to Forest Ghost House.
Forest Ghost House
Go through the level as normal until you reach the door that leads to the level exit. You'll need to go past it and the Big Boo to make your way to the second secret door.
You'll know you made it through the proper door if you see a 3-Up Moon near the exit.
Go through the exit and you'll unlock a secret path to Forest of Illusion 1. Completing the level normally will unlock the path to Forest of Illusion 4.
Forest of Illusion 4
Once you're past the checkpoint, there will be an elevated blue pipe with a Lakitu inside it. Go through it and you'll find the key and keyhole.
Insert the key in the keyhole and you'll unlock the path to Forest Secret Area. Complete that and Forest Fortress and you will unlock the path to the fourth Star World warp point.
Chocolate Island
Chocolate Island 2
In order to reach the secret area, the timer must be at 250 or above. This is what the path will look like if you're quick enough.
Make your way all the way to the right and you'll find a key and keyhole.
Insert the key and you'll unlock the path to Chocolate Secret. Completing that will unlock a shortcut to #6 Wendy's Castle. Completing the level normally will unlock the path to Chocolate Island 3.
Chocolate Island 3
Go through the level normally until you make it to the end. You will have to fly with a Cape under the regular exit to make it to the secret exit. Get a run-up and begin flying to the right until you make it to the secret exit.
Completing the level will unlock the path to Chocolate Fortress. Completing the level with the regular exit will unlock a pointless path that loops back around to the same level.
Valley of Bowser
Valley of Bowser 2
Go through the level normally until you get through the second pipe and you make it past the first sand tide. Get on top of the sand tide and jump up to the top of the ceiling.
Keep running left until you make it to the key and keyhole.
Insert the key and you'll unlock the path to Valley Fortress. Completing that will unlock the path to the Back Door, which allows you to skip most of the levels and Bowser's Castle.
Valley Ghost House
Keep going through the level normally until you get through the door. Run all the way to the right until you reach the last door in the corridor.
Carry the P-switch with you and run to the right until you reach a question mark block.
Intentionally turn yourself into small Mario if you haven't already, and hit the P-switch and then quickly hit the question mark block. You'll have to quickly steer the line of blocks to go to the right.
Keep going up and right until you see a small alcove with a key. While you could theoretically squeeze through the gap as big Mario, it is a lot harder and more precise, so being small Mario is preferable.
Pick up the key and run to the right towards the keyhole.
Insert the key and you'll unlock a secret path to #7 Larry's Castle. Completing the level normally will unlock the path to Valley of Bowser 3.
Valley of Bowser 4
Obtaining the key requires Yoshi. You can obtain him during the level, but if you lose him, you cannot get through the secret exit at all. Go through the level as normal until you reach the end, where you'll find a key and keyhole.
Pick up the key with Yoshi's tongue.
Insert the key and you'll unlock the path to the fifth Star World warp point.
Star World
Note that beating the levels through the normal exits counts as an exit, even if they technically don't lead you anywhere.
Star World 1
The key and keyhole are located to the far right of the level. Simply go to the far right of the first rows of blocks and spinjump your way down until you make it to the key and keyhole.
Insert the key and you'll unlock the path to Star World 2.
Star World 2
The key and keyhole are located in an alcove near the pipe leading to the normal exit. Swim under the floor and continue swimming forward until you make it to the key and keyhole.
Insert the key and you'll unlock the path to Star World 3.
Star World 3
The key and keyhole are located in an alcove above the ceiling. Fly up next to the blue block that's highest out of the 4 blue blocks above ground. Then go in either the left or right direction once you're above the stone blocks.
The key is located to the left, and the keyhole is on the right. Grab the key by hitting the question mark block on the left, and bring it to the keyhole. You'll unlock the path to Star World 4.
Star World 4
Reaching the keyhole requires either spinning into the question mark block on the ground with the Cape, or using a shell to release it. However, the second method cannot be done without activating the red blocks. Assuming you read the guide all the way through, you'll have them already activated. Simply fly or proceed through the level until you see a Koopa kicking a shell into a wide hole. Then grab the free shell next to the hole and kick it forward on the red blocks into the question mark block.
But if you want to complete the game with 11 exits at some later point, or just want to do Star World early, then you'll have to fly through the bottom of the level. Get P-speed and obtain flight on the first platform, then stay as low as possible, until you see the second column of Koopa Paratroopas.
After that, gain height until you're above the darker bottom part of the level background. If done correctly, you'll safely make it onto the platform with the key.
Insert the key into the keyhole and you'll unlock the path to Star World 5.
Star World 5
Reaching the key requires either proceeding on the block path above the level, or flying into the small alcove with the key and keyhole if you don't have the blue blocks activated. The former can be done by either guiding the coin path to the blocks, or flying up there with the Cape. The latter can be done by reaching the platform with a Koopa Troopa and 2 Spinies.
Clear the path and get a run up from the right edge of the platform to fly up through the small hole. Try adjusting to the left in order to have a better chance of making it.
Insert the key and you'll unlock the path to the Special World. Completing the level normally will unlock the path to Star World 1.
Special World Tips
All the levels in the Special World don't have any secret exits, but I still want to provide some general tips to make them slightly more tolerable to play.
Gnarly: You can use the block to the far right in the first row of blocks to climb the level slightly quicker.
Tubular: This level fucking sucks. However, I was able to make completions more consistent by using a specific route. A map of the general route I use can be found here.
Way Cool: You can use Yoshi to complete the level quickly. Go through the yellow pipe near the end of the first moving platform segment and grab Yoshi.
Then, grab the wings by hitting this question mark block and touching the wings while riding Yoshi. You can either complete the minigame or instantly fall down to the bottom to exit the level.
Awesome: Grab the P-switch and bring it to where the Shell-less Koopa Troopa kicks the yellow shell.
Then, hit the P-switch and grab the Star from this question mark block.
Proceed through the rest of the level until you reach the Koopa Paratroopa. Wait until your star runs out, and make sure to stay to the right side to stop the Cheep Cheeps from spawning. Afterwards, jump on the Koopa Paratroopa to reach the block and exit the level.
Groovy: A Cape is recommended for this level. Grab Yoshi from the first question mark block on the ground, and when you get to the Roulette Block, grab a star and run through the level. The Pokeys give hefty amounts of 1-Ups if you proceed to kill them all.
Mondo: This level also fucking sucks. I strongly recommend you grab 2 Cape Feathers for this level. This will greatly help with survivability against the Cheep Cheeps and Amazing Flyin' Hammer Brothers. If you lose one, it's not a big deal. There is a question mark block containing a Feather if you're in a powered up state, in case you lose one in the beginning.
If you lose them all, I really suggest dying and re-doing the level with the Cape. I can't stress how much having Cape Feathers helps with making the level far less tedious.
Once you make it to the 2 rows of question mark blocks, you can simply fly over the final Amazing Flyin' Hammer Brother by getting P-speed on the top row.
I'm skipping Outrageous and Funky because there really isn't much you can do, other than either flying through them entirely or just being good at surviving through them.
Once you finish all the levels of the Special World, you'll unlock a warp point to Yoshi's House, and the game changes into a Fall theme. Isn't that nice?
If you don't like the theme, you can wait until you finish every other level in the game before tackling Special World. Alternatively, you can save Funky for last and continue through the rest of the game, then come back and complete it.