Ask API. GET https://whichemulator.wtf/ask answers questions from the same data as this page, and it is the only place the setup steps are published. It takes the question as q and, optionally, this page's path as page, and returns JSON with answer, sources and follow_ups, or Markdown with Accept: text/markdown. No key needed.
curl -G 'https://whichemulator.wtf/ask' --data-urlencode 'q=Which 3DO emulator should I use on a Mac?' --data-urlencode 'page=/3do/'Questions it answers:
Panasonic 3DO Interactive Multiplayer, Panasonic, 1993. A licensed format: GoldStar, Sanyo and Creative built 3DO machines too.
whichemulator.wtf calls its recommendation for each system the Gold Cartridge pick. For the 3DO, the Gold Cartridge pick is Opera (RetroArch core).
There is no good, maintained standalone 3DO emulator, so the pick is RetroArch with the Opera core. Opera started as the libretro port of 4DO and is the only 3DO emulator still being worked on, with fixes landing through 2026. It runs most of the library and works wherever RetroArch does. It isn't open source in the strict sense: the code is LGPL, but the FreeDO terms it inherits forbid commercial use.
Runs on Windows · Mac · Linux · Android · iOS. Closed source. Download: https://docs.libretro.com/library/opera/
Retail BIOS recommended: Current Opera builds start games with a built-in open boot ROM, but it is new and skips parts of the real BIOS. For the best compatibility, dump the BIOS from your own console (a Panasonic FZ-1 or FZ-10, for example) into RetroArch's system folder. A few Japanese games also need the kanji font ROM.
One controller: If a game ignores your input, set Opera's Active Devices option to 1. Emulating several pads at once confuses some games.
Install it from Online Updater > Core Downloader > The 3DO Company - 3DO (Opera).
Every standalone 3DO emulator has stopped. FreeDO never left beta, 4DO’s last release was in 2016, and Phoenix hasn’t been updated in years. Opera began as the RetroArch port of 4DO and is the one still being worked on, so for 3DO the RetroArch core is the sensible place to start rather than a fallback.
Opera’s source is public and based on the LGPL, but every core file still carries FreeDO’s extra terms, which take precedence: commercial use is forbidden without the original authors’ approval. That rules it out as open source under the usual definition, which is why it is marked closed here. 4DO has the same terms.
In October 2026 Opera gained a built-in, open-source boot ROM called opera-boot, which it now selects by default. It can start games without a retail BIOS, but it is brand new and skips parts of what the real BIOS does. If a game won’t start, switch the BIOS option to the retail one you dumped from your own console.
Reference: WEM-3DO-I83R