[Tool] PokeBridge — move your Pokémon up the gen chain in your browser (Gen 1–5 → BW/B2W2 or Ultra Sun/Moon)

[mrshall]

Hey all. I built a small, free, browser-based tool for a problem I kept hitting while rebuilding a cross-generation living dex: getting older-gen Pokémon up the chain without the multi-cartridge / Poké Transporter shuffle.

▶ Use it (no install, runs in your browser): https://mrsnicoleahall.github.io/PokeBridge/
Source / code: https://github.com/mrsnicoleahall/PokeBridge

Why, when PKSM already does this?
Full respect to PKSM. It's brilliant and absolutely covers this ground. But I'm a bit of a purist, and I wanted a tool that does exactly one thing and nothing else. PKSM and PKHeX are full editors; they can change your Pokémon, and for my own living dex I didn't want that capability anywhere near it. PokeBridge is deliberately transfer-only: it moves my legitimately-caught Pokémon up the chain without editing them (no buffing stats, no altering moves/nicknames/anything). It only does the honest format conversion that moving up a generation requires, the same kind the official Pal Park / Poké Transfer do. And it does whole boxes at once, not one at a time. That's the entire pitch: a clean, faithful, bulk transfer chain and nothing more.

What it does
Load a save, pick a Pokémon (or a whole box), and it converts and drops them into a newer save:

• Sources: Gen 1 (R/B/Y), Gen 2 (G/S/C), Gen 3 (R/S/E/FR/LG), Gen 4 (DPPt/HGSS), Gen 5 (BW/B2W2)
• Destinations: Gen 5 (Black/White, Black 2/White 2) or Gen 7 (Ultra Sun/Ultra Moon)
• From a Gen-7 save you can then use the game's native Bank/HOME link, so it also sidesteps Poké Transporter's one-box-at-a-time limit when building a dex.

Notes

• 100% client-side. Saves are read and written entirely in-browser; nothing is uploaded. (Static site, check the source.)
• Reads .sav, auto-strips DeSmuME .dsv/.dst footers. In Chromium you can open the save off disk and write it back in place; other browsers fall back to a download.
• Whole-box "Transfer all," and it skips Pokémon that can't legitimately move up (eggs, species not in the destination dex) instead of failing.
• Scope is intentionally narrow: a transfer tool, complement to PKHeX/PKSM, not a replacement. No legality editing.
• Known gaps (honest): Gen 1/2/3 transfers currently leave held item and ability unset (they need cross-gen lookup tables); Gen 7 met-data is minimal. Species/level/moves/IVs/EVs/nickname carry over fine.
• Test on a backup save first, especially the Gen 7 write path.

Credits: built test-first against real saves, leaning on ProjectPokemon's Gen III/V save-structure docs and PKHeX's open-source format/checksum work for the Gen 7 bits. Thanks to this community for documenting all of it.

Feedback / bug reports welcome, just open an issue on the repo.