Before diving in
In-browser apps: Local execution in your browser, powered by JavaScript, Web Assembly. Cloud-based apps: Remote execution on servers, accessed through various interfaces.
These emulators run off any modern PC internet browser. Check this list for more browser-based emulators.
Each entry is system specific, for multisystem see the multisystem entry at the bottom.
Nintendo
editNES / Famicom
- EM-FCEUX (Emscripten port for FCEUX)
- GoNES (Written in Go)
- jsNES (git)
- Toploader - JSNES (Frontend to jsNES)
- cfxnes
- NESVibes
SNES / Super Famicom
Nintendo 64
Nintendo Handhelds 
Game Boy / Color
Game Boy Advance
- PicoAdvance
- SkyEmu (Accurate)
- gbaJS (mGBA dev)
- gba.ninja (VBA-M port)
- 44VBA (WASM port of VBA-M)
Nintendo DS / Virtual Boy
Sega & Sony
editMaster System / Game Gear
Genesis / Mega Drive
Dreamcast
PlayStation
PlayStation 2
PlayStation Portable
Personal Computers
editApple I / II
Macintosh
PC & Microsoft
IBM PC / MS-DOS
- PCjs (8086/80286/80386/etc)
- v86 (x86-to-wasm JIT, supports Win 1.01 to Win 2000, Linux, etc.)
- Halfix
- MartyPC
- DOSee
- RetroTick (x86/ARM TypeScript emulator for Win32/Win16/DOS)
MSX
Other Computers
- Atari 8-bit/ST: jsA8E, EstyJS.
- Sharp MZ: MZ700-js.
- BBC Micro: jsbeeb.
- ZX Spectrum: ZX Spectrum XYZ.
Multi-System & Libraries
editInternet Archive (MESS)
- Console Living Room (Bally Astrocade, Atari 7800, Entex Adventure Vision, Amstrad GX400, etc.)
- Software Library (Computers: ZX Spectrum, Atari, Apple II)
- Software Library: MS-DOS Games
- Software Library: MS-DOS Games online emulator
Multi-System Engines
- EmulatorJS: (Used by MyEmulator.onl, Emulator.onl, EmulatorOnline.xyz, Rec0ded88)
- My Emulator Online: (PSP, NDS, GBA, GB, N64, Genesis, Neo Geo, SNES, NES)
- Afterplay: (NES to PlayStation)
- Eclipse: (GB, GBA, GBC, NES, SMS, GG, SNES)
- Virtual Console: (JS emulator collection)
- WAVE: (CHIP-8, GB, GBC, GBA/DS)
- jgenesis: (NES, SNES, SMS, GG, Genesis/Mega Drive, CD, 32X, GB, GBC)
- RetroArch / WebRetro: webretro, Libretro Web, binbashbanana
- Pantheon: (Atari 2600, ColecoVison, Commodore PET, SEGA SG-1000, SMS, ZX80/81/Spectrum)
- RetroVault: (NES, SNES, N64, GameCube, Genesis, Dreamcast, PS1, Xbox, TG-16, Lynx)
- Obentou: (NES, GBC, PCE, TMS80, Space Invaders, Pac-Man, CHIP-8, WATARA, PV1000, Bytepusher)