Side-by-side: suspected Gemini 4 Pro vs Gemini 3.8 Flash in LMArena

CodeByPoonam · x · 2026-09-18

Users report LMArena is routing "gemini-3.8-flash" traffic to a new Gemini Pro mode. A same-prompt side-by-side comparison shows the new mode outputting noticeably better results, supporting speculation that 3.8 Flash is actually a stealth Gemini 4 Pro test. Google hasn't confirmed.

Related event: Suspected Gemini 4 Pro quietly testing on LMArena under "3.8 Flash" alias(13 posts)→

Original post →

More from Models

Models channel →