Gen I–V · runs locally · The Shuffle
Pokémon Randomizer
Randomize your Pokémon ROM right in the browser — no Java, no install, no upload. 122 options, five presets and a direct handoff to your tracker.
Same game. New world.
A new world, not a new game.
Randomize Pokémon ROMs from Red to Black 2 in your browser: 122 options, five presets, seeds, spoiler logs. Your ROM never leaves your device.
122randomizer options
5starting presets
0 bytesof your ROM uploaded
- Balanced
- Classic
- Hardcore
- Chaos
- Quality of life
0 bytes uploaded. Processed in your browser.
Features
Everything a run needs.
Your ROM stays with you
Every step runs in a Web Worker inside your browser. The ROM file is never uploaded — not even for Nintendo DS games.
122 options
Wild encounters, trainers, starters, movesets, abilities, types, evolutions, TMs, items, shops and more.
Five presets to start
Balanced, Classic, Hardcore, Chaos and Quality of life — then fine-tune everything and save your own presets.
Seeds and shareable recipes
Recipes store the seed, engine version and checksums, never ROM bytes. Share them as a file or a link.
Spoiler log
Download the full log of what changed — or keep the surprise and never open it.
Straight into your run
Send the randomized world to your SoulLink or Nuzlocke run: real types, stats, boss teams and level caps included.
Gen I to Gen V
Official main-series games from Red, Blue and Yellow to Black 2 and White 2.
Proven engine
Based on Universal Pokémon Randomizer ZX (GPL). The complete source, including the browser bridge, is available to download.
How it works
From first encounter to last badge.
Open your ROM
Select your own, unmodified cartridge dump. It is read locally.
Pick a preset
Start from Balanced, Classic, Hardcore, Chaos or Quality of life.
Tune the options
Adjust any of the 122 settings, choose starters and limit generations.
Download and play
Save the new ROM, the recipe and the spoiler log — or hand the world to your tracker.
Supported games
Generation I to V.
The randomizer supports the official main-series games of generations I–V. Each guide lists the original level caps and boss teams — randomized worlds get their real caps in the tracker.
FAQ
Good to know.
Is my ROM uploaded?
No. The randomizer runs entirely in your browser. Only if you send the result to an online tracker run is the structured world data (not the ROM) stored with that run.
Which games can I randomize?
Official main-series games of generations I–V: Red, Blue, Yellow, Gold, Silver, Crystal, Ruby, Sapphire, Emerald, FireRed, LeafGreen, Diamond, Pearl, Platinum, HeartGold, SoulSilver, Black, White, Black 2 and White 2. ROM hacks are not guaranteed to work.
Do I need Java?
No. The Universal Pokémon Randomizer ZX engine has been compiled to run in the browser, so there is nothing to install.
Can my friends play the same randomized world?
Yes. Share the recipe: the same seed and settings on the same ROM produce an identical result, which is ideal for SoulLink runs.
Where do I get a ROM?
Use a dump of a cartridge you own. PokéRuns does not provide or link to ROM files.
Guides
Read before you run.
Setup guide
Randomizer Nuzlocke
Set up a fair randomizer Nuzlocke: which settings matter, how the five presets differ, sharing seeds for Soul Links and rule tweaks for random worlds.
Rules guide
Soul Link rules
How a Soul Link Nuzlocke works: linked encounters, shared losses, the primary type rule, the gender clause and tips for playing with two to four trainers.
Ideas
Nuzlocke variants
Hardcore, Soul Link, Randomizer, Monotype, Genlocke, Wonderlocke, Egglocke and difficulty ROM hacks — how each Nuzlocke variant works and who it is for.
Shuffle a ROM.
Free, no ads and no account needed. Your ROM never leaves your device.