Tested Gemini 3.1 Pro Preview:
Token-efficiency update with claimed improvements in toolcalls and overall agentic reliability.
Verbosity went down ~25% overall, reasoning by 32%. Very light thinker, akin to GPT-5-Mini.
In the same breath, long context pricing has been increased above 200k ctx ($2/12 → $4/18). This same price increase is also applied to Gemini 3 Pro.
- Output quality was largely equivalent to Gemini 3 Pro
- Produced less complex code, and performed slightly worse on the most complex tasks
- Censorship was tighter than on 3 Pro
Vision was top notch, sharing first place with Gemini 3 Flash.
Chess play was noticeably impacted by the reduced reasoning. In contrast to Gemini 3 Pro, an undefeated beast holding 60+ matches without a single loss* (not accounting for 2 human players), Gemini 3.1 Pro already lost 5 times during initial placement matches (0-2 vs 3 Pro). Move accuracy, and legality are still very strong, but the unique sharpness in key moments seems to have been partially lost.
Overall, it's still a strong model and will be significantly cheaper for short-context tasks.
Compared to Gemini 3 Pro Preview however, to me this is a downgrade and feels like an economically driven release. YMMV.
Update: The day after my initial Chess disappointment, I ran several more mirror matches and while blind continuation play favors Gemini 3 Pro, full information reasoning chess actually ended up being a close 3-2 series. All matches are viewable here: Replays