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Head-to-head · Sega Master System Emulators

Gearsystem vs Nexen

  • Updated Oct 2026
  • Both researched from official sources
  • 6 checks side by side
Higher score Gearsystem #1 in Sega Master System Emulators 9.4/10 Free plan Free plan✓ 3 of 5 features Visit Gearsystem
Nexen #7 in Sega Master System Emulators 8.0/10 Open source ✓ 1 of 5 features Visit Nexen

Gearsystem leads on 0 checks, Nexen on 0, and 6 are even. Who comes out ahead on the 6 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreGearsystem · 9.4/10
  • Free planonly Gearsystem
  • Most featuresGearsystem · 3 of 5

Gearsystem scores higher on our rubric for sega master system emulators: 9.4 against 8.0 out of 10; our editors rank them #1 and #7.

Gearsystem is the better fit for most users wanting a full-featured SMS emulator. Nexen is the better fit for TAS and multiplayer-focused desktop users.

  • Gearsystem fits best

    Most users wanting a full-featured SMS emulator

  • Nexen fits best

    TAS and multiplayer-focused desktop users

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Side by side

Feature Gearsystem 9.4/10 Visit ↗ Nexen 8.0/10 Visit ↗
At a glance
Editor score 9.4 8.0
Ranking #1 in Sega Master System Emulators #7 in Sega Master System Emulators
Best for Most users wanting a full-featured SMS emulator TAS and multiplayer-focused desktop users
Pricing model Free Free
Starting price Free plan Open source
Free plan ✓ (best) Not checked yet
Free trial — —
Deployment Desktop, Mobile Desktop
Platforms Web, Windows, macOS, Linux, iOS, Android Windows, macOS, Linux
Support Community Community, Docs
Built for Solo, Small business Solo, Small business
Features Gearsystem 3/5 · Nexen 1/5
Source available ✓ (best) Not checked yet
Built-in debugger ✓ (best) Not checked yet
Netplay support Not checked yet ✓ (best)
Cheat support ✓ (best) Not checked yet
BIOS required — Not checked yet
Specs
Supported platforms Windows, macOS, Linux, BSD, RetroArch, Android, iOS, tvOS, webOS, Emscripten and other Libretro targets Not checked yet
Our review
Pros
  • Supports Master System, Mark III, Game Gear and SG-1000 software
  • Includes save states, rewind, cheats and a full debugger
  • Runs across desktop, mobile, web and Libretro-supported platforms
  • Rollback netplay supports multiplayer across Windows, macOS, and Linux.
  • Frame-by-frame TAS editing includes undo/redo and greenzone support.
  • Timestamped save states, debugger tools, shaders, and recording add depth.
Cons
  • The full debugger may be more than casual players need
  • Gear-to-Gear communication is documented for local desktop processes
  • Network netplay is not part of the documented feature set
  • It is limited to Windows, macOS, and Linux desktop computers.
  • Its broad system coverage may exceed the needs of SMS-only users.
  • Several additional systems remain under development.
Our verdict

Gearsystem is an open-source C++ emulator for Sega Master System, Sega Mark III, Game Gear, SG-1000 and Othello Multivision software. It is aimed at players who want more than basic ROM playback, as well as developers and enthusiasts who…

Read the review →

Nexen is an open-source multi-system emulator for Windows, macOS, and Linux. It supports Sega Master System and Game Gear alongside NES, SNES, Game Boy, Game Boy Advance, PC Engine, WonderSwan, and Atari Lynx. That makes it a fit for…

Read the review →
  1. GearsystemSega Master System Emulators 9.4Free plan
  2. NexenSega Master System Emulators 8.0Open source

Strengths and trade-offs

  • Gearsystem — where it wins

    • Supports Master System, Mark III, Game Gear and SG-1000 software
    • Includes save states, rewind, cheats and a full debugger
    • Runs across desktop, mobile, web and Libretro-supported platforms

    Where it doesn't

    • The full debugger may be more than casual players need
    • Gear-to-Gear communication is documented for local desktop processes
    • Network netplay is not part of the documented feature set

  • Nexen — where it wins

    • Rollback netplay supports multiplayer across Windows, macOS, and Linux.
    • Frame-by-frame TAS editing includes undo/redo and greenzone support.
    • Timestamped save states, debugger tools, shaders, and recording add depth.

    Where it doesn't

    • It is limited to Windows, macOS, and Linux desktop computers.
    • Its broad system coverage may exceed the needs of SMS-only users.
    • Several additional systems remain under development.

More comparisons

All sega master system emulators comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update