Is LMArena quietly testing a Gemini 4 stealth model? SVG quality sparks suspicion

Background-Youth7289 · reddit · 2026-09-20

A Reddit user compared anonymous LMArena models on an SVG 'horse riding a bike' prompt. The model labeled Gemini 3.8 Flash High took 30 minutes to render vs 5 minutes for Claude Fable 5.1 High — opposite of earlier reports — and produced dramatically better output than expected from a Flash-tier model. The author suspects LMArena was quietly testing an experimental, possibly Gemini 4-generation model under that label, though it's unverified speculation. Worth watching for corroborating reports.

Original post →

More from Models

Models channel →