Where to Play Sonic Games Online (Official & Browser)

Official and legal ways to play Sonic games online/browser:

Official Stores (Download Required)

• Steam: Sonic Mania, Sonic Origins, Sonic Frontiers, Generations, Colors Ultimate, Lost World — frequent sales ($5–$15).
• Epic Games Store: Free giveaways occasionally (Sonic Mania 2021).
• GOG.com: DRM-free Sonic CD, Sonic 3 & Knuckles (via Sega Genesis Classics).
• Console Stores: PSN, Xbox, eShop — same titles.

Browser / No-Download (Legal)

• Sega Genesis Classics (Web) — Sega's official emulator portal (discontinued 2020, but mirrors exist).
• Internet Archive (Archive.org) — "Software Library: Sega Genesis" — play Sonic 1, 2, 3, & Knuckles, CD, Spinball in-browser (JS emulator). Legal gray area; Sega tolerates.
• Sonic Fan Games HQ / Sonic Retro — Links to Sonic Robo Blast 2 (SRB2), Sonic GT, Sonic Utopia — free fan games (PC download, not browser).

Mobile (Free)

• Sonic Dash / Sonic Forces: Speed Battle — Endless runners (iOS/Android).
• Sonic the Hedgehog Classic (Sega Forever) — Ad-supported ports of Sonic 1, 2, CD.

Multiplayer

• Sonic Mania Plus — Local co-op + "Encore Mode" (no online).
• Sonic Frontiers — Single-player only.
• SRB2 (Fan) — Netplay supported (up to 32 players).

Avoid: "Sonic.exe" creepypasta ports, shady APKs, sites asking for surveys. Stick to Steam/GOG/Archive.org.