Can the DSi XL Play Game Boy Games? Virtual Console vs. Flashcarts vs. 3DS

No native cartridge support. The DSi/DSi XL lacks the Game Boy / Game Boy Color hardware (Sharp LR35902 CPU, 5V voltage levels, cartridge bus) entirely. The GBA slot (Slot-2) was removed.

Official Option: DSiWare / Virtual Console (Delisted)

• Nintendo released select GB/GBC titles as DSiWare on the DSi Shop (closed March 2017).
• Examples: Mario's Picross, Link's Awakening DX, Wario Land, Tetris, Game & Watch Gallery, Dr. Mario, Balloon Fight.
• No longer purchasable. If you bought them previously, you can redownload via "Previously Downloaded" in the DSi Shop (servers still online for now).

Unofficial Option: Flashcarts & Homebrew

• Slot-1 Flashcart (ezFlash Omega, R4i Gold 3DS Plus, Supercard DSTWO) + Goomba Color / Lameboy emulators — runs GB/GBC ROMs from microSD.
• DSi Homebrew (Unlaunch / HiyaCFW + TWiLight Menu++): Installs emulators to internal NAND; boots directly from menu. Best integration.

Best Legal Experience Today

Nintendo 3DS / 2DS family: Full native backward compatibility with Game Boy, Game Boy Color, and Game Boy Advance via:

• Virtual Console (eShop — closed but installed titles work)
• Open_AGB_Firm (custom firmware) — near-perfect GBA hardware simulation
• Original GBA cartridges via Slot-2 (on 3DS/2DS models that have it)

For authentic, legal, high-quality GB/GBC play on modern hardware, a 3DS/2DS with CFW is the gold standard.