Gemini 1.5 Pro vs Gemini 3.1 Pro Preview
Compare Gemini 1.5 Pro and Gemini 3.1 Pro Preview, both from Google AI, context windows of 1.0M vs 1.0M, tested across 18 shared challenges. Updated June 2026.
Which is better, Gemini 1.5 Pro or Gemini 3.1 Pro Preview?
Gemini 1.5 Pro and Gemini 3.1 Pro Preview are both competitive models. Gemini 1.5 Pro costs $3.5/M input tokens vs $2/M for Gemini 3.1 Pro Preview. Context windows: 1000K vs 1049K tokens. Compare their real outputs side by side below.
Key Differences Between Gemini 1.5 Pro and Gemini 3.1 Pro Preview
Gemini 1.5 Pro is made by google while Gemini 3.1 Pro Preview is from google. Gemini 1.5 Pro has a 1000K token context window compared to Gemini 3.1 Pro Preview's 1049K. On pricing, Gemini 1.5 Pro costs $3.5/M input tokens vs $2/M for Gemini 3.1 Pro Preview.
Per 1M tokens
Gemini 3.1 Pro Preview wins input (1.8× cheaper)·Gemini 1.5 Pro wins output (1.1× cheaper)
No community votes yet. On paper, Gemini 3.1 Pro Preview has the edge — bigger model tier, newer.
Style Comparison
Gemini 3.1 Pro Preview uses 8.9x more headings
