Man, the 90s were a wild time for gaming. You didn't have a Wiki or a 4K walkthrough on your phone. You had playground rumors and those thick, overpriced strategy guides. If you wanted to break the game, you had to work for it. Pokémon Blue cheats codes aren't just strings of hex values; they are the DNA of a generation’s gaming experience.
Most people think of cheating as a way to skip the hard parts. In Pokémon Blue, it was different. It was about discovery. It was about finding the stuff Nintendo didn't want you to see. Honestly, half the "cheats" weren't even codes you typed in—they were glitches that acted like codes. We’re talking about a game held together by digital duct tape.
Why the MissingNo Glitch is Still the King of Pokémon Blue Cheats Codes
The most famous "cheat" in the history of the franchise isn't a GameShark code. It’s a sequence of events. You know the drill. Talk to the old man in Viridian City, let him show you how to catch a Weedle, and then fly straight to Cinnabar Island. Surfing along that specific eastern coastline isn't just a trip to the gym; it’s a gateway to the void.
MissingNo is a programming oversight. Basically, the game uses that strip of water to buffer data for the last area you visited. Because the "Old Man" tutorial temporarily changes your player name to "OLD MAN," the game stores your actual name data in the memory slot usually reserved for wild Pokémon encounters. When you hit the Cinnabar coast, the game tries to translate the letters of your name into Pokémon levels and IDs.
If your name has specific characters in the third, fifth, or seventh slots, you trigger a "placeholder" Pokémon. That’s MissingNo.
The real prize? Your sixth item slot gets multiplied by 128. If you put a Rare Candy or a Master Ball there, you’re set for life. You've essentially cracked the game wide open without ever plugging in a third-party device. It’s the ultimate "organic" cheat. Just be careful with your Hall of Fame data—MissingNo tends to scramble those pixels into a digital nightmare.
The Reality of GameShark and the Power of Hex
If you wanted the "real" Pokémon Blue cheats codes back in 1998, you needed a GameShark. This chunky plastic brick sat between your Game Boy and the cartridge. It didn't just play the game; it intercepted the communication between the hardware and the software.
It’s actually kinda fascinating how it worked. The GameShark would constantly rewrite a specific memory address with a value you chose. Want infinite money? The code 019947D3 basically screams at the game: "Hey, the first two digits of the money counter are 99!" over and over again, thousands of times a second.
Here are some of the heavy hitters that people actually used:
- Walk Through Walls:
010138CD. This one is dangerous. You can skip the S.S. Anne, bypass the guards who want tea, and walk right into the tall grass before you even have a starter. But if you walk off the map? You’re stuck in a black void until you reset. - Infinite HP:
01FF16D0. It makes battles trivial. It also makes them boring, but hey, if you’re trying to beat Mewtwo with a Level 5 Magikarp, this is your best friend. - The Master Ball Shop:
01017BCF. This replaces the first item in any Poké Mart with a Master Ball for 0 yen. Honestly, this felt like the peak of power as a kid.
The problem with these codes is that they weren't stable. Game Freak didn't design the Game Boy's RAM to be constantly poked and prodded by external hardware. If you left too many codes on at once, the game would crash. Or worse, your save file would vanish into the ether. A lot of kids learned about "data corruption" the hard way because they wanted a Mew.
Finding the Real Mew Without the Rumors
Speaking of Mew, the rumors were exhausting. "Check under the truck near the S.S. Anne!" everyone said. "Use Strength on it!" It was all a lie. The truck is there, sure, but it’s just a decorative asset. There is no Mew under the truck.
However, there is a legitimate way to get Mew using what we now call the "Trainer Fly" or "Mew Glitch." It’s basically a manual entry into the world of Pokémon Blue cheats codes.
You need to find a trainer who can see you from a distance—usually the Gambler on Route 8 or the Jr. Trainer in the grass near Nugget Bridge. You stand just outside their line of sight, press Start, and Fly away at the exact moment you move into their view. The game gets confused. It thinks you’re in a battle, but you’re actually flying to Lavender Town.
After you fight a specific trainer (usually the Youngster with the Slowpoke on Route 25), you walk back toward Route 8. Your menu will pop open on its own. Close it, and boom—a Level 7 Mew appears. This isn't a mod. It isn't a GameShark. It’s just the game’s logic failing to account for a player being in two places at once. It’s beautiful in its jankiness.
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The Risks: Why Your Save File is Screaming
Let's be real for a second. Using Pokémon Blue cheats codes—specifically the hardware-based ones—is a gamble. The Game Boy has a very limited amount of RAM. When you use a "Catch any Pokémon" code, you’re overriding the encounter tables.
If you use a code to encounter a Pokémon that isn't supposed to exist in that area, or a Pokémon whose ID number is outside the 1-151 range (like the "M" hybrid or other glitch Pokémon), you risk overwriting the pointers for your save data.
I’ve seen dozens of cartridges where the "New Game" option is the only thing left because someone tried to force a Celebi into a game that didn't know what a Celebi was. Pokémon Blue doesn't have a backup save. Once it's gone, it's gone.
If you are playing on original hardware, keep your cheats localized. Turn the code on, get the item or Pokémon, save, and turn the code off. Don't play the whole game with "Walk Through Walls" active. You will eventually walk into a script trigger that the game can't handle, and you'll be soft-locked forever.
Practical Next Steps for the Modern Trainer
If you’re revisiting the Kanto region in 2026, whether on an original handheld or an emulator, you have better tools than we did. But the old rules still apply.
- Backup your save data first. If you’re on an emulator, use Save States before you input any hex codes. If you're on a physical cart, consider using a device like a GB Operator to pull your save file to a PC before you start messing with GameShark values.
- Use the "Mew Glitch" instead of codes. It is safer for the internal logic of the game because it uses the game’s own battle engine to generate the encounter rather than forcing a memory override.
- Check your Item ID list. If you’re using the "Buy any item" cheat, make sure the hex value matches the internal index of Pokémon Blue. Using a Gold/Silver item ID in Blue will result in a "Teru-sama" or a game crash.
- Prioritize the MissingNo glitch for items. It’s the most efficient way to get infinite Master Balls and Rare Candies without needing external hardware. Just remember that viewing your Hall of Fame after doing it will show you a garbled mess of pixels. It won't break the game, but it looks scary.
Pokémon Blue is a masterpiece of "good enough" programming. It’s a game that lets you under the hood if you know which bolts to loosen. Whether you're doing it for nostalgia or to finally catch 'em all, these cheats are part of the heritage of the series. Just don't blame me if your rival's name turns into a string of question marks.
Your next move is to verify your current party's stats. If you've used Rare Candies to level up, remember that your Pokémon will have lower stats than those leveled through manual battling because they haven't earned "Stat Experience" (the precursor to EVs). To fix this, deposit your Pokémon in the PC and take them back out; this triggers a stat recalculation that can help bridge the gap.