Delta Emulator iOS — Complete iPhone Setup Guide 2026

Install Delta from the App Store

Open the App Store and search for Delta. The developer is Riley Testut / AltStore LLC. It is free and ad-free with no IAP. Tap Get to install.

Delta supports: Game Boy Advance, Game Boy Color, Game Boy, Super Nintendo, NES, Nintendo 64, Nintendo DS, and Sega Genesis. Each system gets its own tab in the library.

Get your ROM files (legal path)

Delta does not include game files. You must supply ROM dumps of games you own. Dumping your own cartridges is the legally clearest path:

• GBA / GBC / GB: GB Operator by Epilogue or GBxCart RW
• SNES: Cartridge Reader (or Super UFO Pro 8)
• N64: 64drive or UltraSave
• NDS: GodMode9 on a modded 3DS

Supported file extensions by system: GBA → .gba; GBC/GB → .gbc / .gb; SNES → .sfc or .smc; NES → .nes; N64 → .z64, .n64, or .v64; NDS → .nds; Genesis → .md, .bin, or .gen.

Transfer ROM files to iPhone

The simplest method is to place ROM files in iCloud Drive, Dropbox, or Google Drive. They become accessible through the iOS Files app.

Alternatively, AirDrop files directly from a Mac to the Files app.

Import a game into Delta

1. Open Delta.
2. Tap the + button in the top-right of any library screen.
3. Choose Files and navigate to your ROM file.
4. Tap the file — Delta imports it automatically into the correct system tab.
5. Tap the game tile to launch it. On-screen overlay controls appear immediately.

Most systems in Delta run without a BIOS file. Nintendo DS is the main exception.

Nintendo DS — three BIOS files required

Without them, many NDS games fail to start or show a white screen. These files must be dumped from a real Nintendo DS (they are not legally redistributable):

• bios7.bin — ARM7 BIOS, 16 KB
• bios9.bin — ARM9 BIOS, 4 KB
• firmware.bin — NDS firmware, 256 KB

How to add NDS BIOS files:

1. Open Delta → Settings (gear icon, top-left).
2. Scroll to the Nintendo DS section.
3. Tap each BIOS slot and select the corresponding file from the Files app.
4. All three slots must show a green checkmark for full NDS compatibility.

Nintendo 64 — BIOS not required

Delta uses high-level emulation for N64 and boots the vast majority of N64 titles without a BIOS. If a specific game crashes, check the Delta compatibility list at delta-emulator.app — most issues are game-specific, not BIOS-related.

GBA — no BIOS required

Delta includes a built-in GBA BIOS replacement compatible with nearly all GBA titles. A small number of homebrew titles or games with unusual startup routines may behave differently, but this is rare.

Delta supports external controllers via Bluetooth or a wired Lightning/USB-C connection.

Pair a Bluetooth controller before opening Delta

• Xbox Series X/S controller: Hold the pairing button on top until the Xbox button blinks rapidly. In iOS Settings → Bluetooth, select Xbox Wireless Controller.
• PS5 DualSense: Hold Create + PS button until the light bar flashes. Select DualSense Wireless Controller.
• PS4 DualShock 4: Hold Share + PS button. Select DUALSHOCK 4 Wireless Controller.
• MFi controllers (Backbone One, Razer Kishi): Connect via Lightning or USB-C. Recognized immediately, no pairing needed.

Once the controller is connected and Delta is open, navigate to Delta → Settings → Controllers to verify it is detected. Delta auto-maps buttons to each system's layout. You can customize button mapping per system from the same screen.

On-screen controls

Delta's on-screen overlay renders the original controller face for each system. To adjust size, opacity, or button placement: tap the three-dot menu inside a game → Controller Skin. Community-made .deltaskin files can be imported by opening the file from the Files app and choosing Open in Delta.

Delta Sync backs up save files and save states to Dropbox or Google Drive. Without it, reinstalling Delta or switching devices loses all save progress.

Enable Delta Sync:

1. Open Delta → Settings → Sync.
2. Choose Dropbox or Google Drive as the sync service.
3. Tap Sign In and authorize Delta with your account.
4. Enable Sync Enabled and select which data to sync: Game Library, Save Files, Save States, Cheats, Controller Skins.

What syncs automatically:

• Save files (.sav): synced after each game session ends.
• Save states: synced when you save state inside a game.
• Game library metadata (titles, cover art — not the ROM files themselves).

To force an immediate sync, tap the circular arrows icon on the Delta home screen.

Conflict resolution: if the same save was modified on two devices while offline, Delta will prompt you to choose which version to keep. Choose the more recent one unless you want to roll back.

Important: Delta Sync does not upload your ROM files to the cloud — only save data. If you reinstall Delta, re-import your ROM files manually (from iCloud Drive, Dropbox, or AirDrop), but your save progress restores automatically from the sync service.