Undertale Timeline Reset Codes: How to Actually Wipe the Slate Clean

You messed up. Maybe you killed Papyrus just to see what would happen, or maybe the guilt of a Genocide run is finally weighing on your soul. Now, you’re looking for Undertale timeline reset codes because the game won't let you forget. Toby Fox designed this game to remember your sins. Even if you hit "Reset," the characters still look at you funny. Flowey still knows what you did.

It’s haunting.

Actually, it’s brilliant game design, but it’s a massive pain when you just want a truly fresh start. Most people think a simple reset from the main menu fixes everything. It doesn't. To get back to "True Reset" status or to scrub the data after a No Mercy run, you have to dig into the save files. There isn't a "cheat code" you type into the console like it's 1998. You have to go into the guts of the game.

The Reality of Undertale Timeline Reset Codes and Save Manipulation

Let’s get one thing straight: there is no secret button combination. If you see a YouTube video claiming that pressing "Up, Up, Down, Down" on the menu screen triggers a total wipe, they're lying to you.

The "codes" people talk about are actually manual edits to the file0, file9, and undertale.ini files. These files live in your AppData folder. If you’re on Windows, you’ll find them by typing %localappdata% into your search bar and looking for the "UNDERTALE" folder. This is where the game stores your "sins."

When you play a Genocide run, the game creates a specific file called system_information_962. That's the one that permanently flags your account as having "sold your soul." Even if you reinstall the game, Steam Cloud Sync will often just put it right back. It's persistent. It's annoying. It's meant to be a consequence.

Breaking the World (And Fixing It)

To perform a manual reset that the game can't track, you have to be precise.

First, turn off Steam Cloud Sync. If you don't do this, Steam will see your empty folder and say, "Hey, buddy, you lost your files! Let me put those back for you," and suddenly your genocide consequences are back. Right-click Undertale in Steam, go to Properties, and toggle off the Cloud Sync.

Now, delete everything in that AppData/Local/UNDERTALE folder. Everything.

👉 See also: F7C Mk2 Ball Turret: The Truth About Why You Can’t Buy It (Yet)

Wait.

There's a catch. If you want to keep your settings but lose your history, you only delete file0 and undertale.ini. But honestly? If you're looking for Undertale timeline reset codes, you probably want the nuclear option. Wipe the folder.

Why the Game Remembers (And Why It Matters)

Toby Fox isn't just being a jerk. The persistence of the timeline is the core of the game's narrative. Characters like Sans and Flowey have a meta-awareness of the player's ability to "Save" and "Load."

When you talk about Undertale timeline reset codes, you're really talking about fighting the game's memory. If you kill Toriel and then immediately reload your save to spare her, Flowey will literally mock you for it. He knows. He saw you kill her.

"I know what you did," he says.

It’s chilling the first time it happens. It’s because the game writes that event to the undertale.ini file the second it happens. It doesn't wait for you to save. The game is constantly taking notes on your behavior.

💡 You might also like: Silent Hill Mannequin Spider: Why the Remake’s Wall-Crawler is Your Worst Nightmare

The Difference Between a Reset and a True Reset

A standard Reset is what you get after a Neutral ending. It resets your stats (LV, HP, EXP), but the "meta-memory" remains. Some dialogue changes. Characters feel like they've met you before.

A True Reset only happens after a True Pacifist ending. This is the only "official" way to get a clean slate without digging into the game files. It wipes almost everything. The characters get their happy ending, and you get a fresh start.

But even a True Reset won't save you from the "Post-Genocide" consequences. If you completed a Genocide run and then did a True Pacifist run, the final scene changes. You see a photo. You see red eyes. You realize that "you" aren't really in control anymore.

Using "Flowey’s Time Machine"

If editing Notepad files feels too risky, the community built a tool called "Flowey’s Time Machine." It’s a web-based save generator. Instead of hunting for Undertale timeline reset codes, you just select the parameters you want.

• Want to be at the start of the game with 0 kills?
• Want to jump straight to the Sans fight?
• Want to erase the "Soulless" flag?

You toggle the switches, and the site spits out a file0 and undertale.ini for you to paste into your folder. It’s the closest thing to a "cheat code" the community has.

But be careful. If you mess up the formatting, the game might crash or just ignore the files. Undertale is surprisingly sensitive to how those files are structured. For example, your name in the game isn't just text; it's tied to specific ID numbers in the save data.

The Linux and Mac Problem

If you're on a Mac or Linux, finding these files is a different headache. On macOS, you’re looking in ~/Library/Application Support/com.tobyfox.undertale/. On Linux, it's usually under your home directory in .config/tobydox/. The process is the same: delete, disable cloud, restart.

Common Misconceptions About Timeline Codes

People often confuse "Fun Values" with reset codes. You might have heard that changing a number in your save file can trigger secret events, like the Gaster followers or the Mystery Man. This is true! This is the "Fun" variable.

But changing your Fun value isn't a reset. It's more like tuning into a different radio frequency. You can see things that aren't usually there, but your history—who you killed, who you befriended—stays the same.

Some players think that if they wait long enough on the black screen after a Genocide ending, the game "resets" itself. It doesn't. You're stuck in a void for ten minutes until Chara offers you a deal. Giving up your soul is the only way back into the game through the "legit" path.

How to Verify Your Reset Worked

You’ll know you’ve successfully used Undertale timeline reset codes (the manual way) if the intro cinematic plays exactly like the first time you opened the game. No shortcuts. No weird glitches.

If you reach the first save point and your name is already filled in, or if Flowey mentions anything about the past, you failed. Something stayed behind. Usually, it's a stray file in the Steam "remote" folder.

Steam keeps a backup of your saves in its own directory, usually under Program Files (x86)/Steam/userdata/[your ID]/391540/. If you really want to be sure, you have to scrub that one too.

Steps for a Total Timeline Purge

To truly achieve what Undertale timeline reset codes are supposed to do, follow this sequence exactly. Don't skip steps or you'll just end up with a "Tainted" save again.

1. Close the game completely. Ensure it isn't running in the background or sitting on a pause screen.
2. Open Steam, go to your library, and right-click Undertale. Under "Properties," find the "General" tab. Turn off "Steam Cloud" synchronization. This is the most common point of failure for players.
3. Navigate to your local save folder. On Windows, use the shortcut Win+R, type %localappdata%, and hit enter. Find the folder named UNDERTALE.
4. Delete every single file in that folder. If you see files named system_information_962 or system_information_963, those are the ones that hold your Genocide run history. They must go.
5. Go to your Steam installation folder. Usually, this is C:\Program Files (x86)\Steam\userdata. There will be a folder with a string of numbers (your user ID). Inside that, look for folder 391540. This is Undertale's cloud cache. Delete the remote folder inside it and the remotecache.vdf file.
6. Launch the game. It should start with the "long ago, two races ruled over Earth" intro.
7. Play until you save for the first time. Once you have a new save, you can exit the game and turn Steam Cloud back on. When Steam asks if you want to use the local file or the cloud file, choose the local file. This will overwrite the "bad" history on Steam's servers with your new, clean timeline.

Doing this is the only way to get a "clean" experience again. It’s a bit of a process, but for a game that remembers everything, it’s the only way to truly make it forget. Whether you're doing this to see a different ending or just because the game's "memory" is getting too creepy, these steps are your actual "reset codes."

There's no magic word, just file management. Be thorough, or Sans will still be waiting for you at the end of the hall, knowing exactly what you did in that other life.