Gemini 3.1 Pro vs GPT-5.2 Codex: Specs & Benchmark Comparison

CharacteristicGemini 3.1 ProGPT-5.2 Codex
CompanyGoogleOpenAI
Release DateFebruary 19, 2026January 13, 2026
Parameters
MultimodalYesYes
Context (input)1.0M400K
Context (output)66K128K
Input Price / 1M$2.50$1.75
Output Price / 1M$15.00$14.00
Average Score0.80.6

Verdict

Gemini 3.1 Pro leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: Gemini 3.1 Pro — 0.8, GPT-5.2 Codex — 0.6.

API Cost

GPT-5.2 Codex is 1.1x cheaper: input $1.75/1M vs $2.50/1M tokens.

Context Window

Gemini 3.1 Pro supports a larger context: 1M vs 400K tokens.

Recency

Gemini 3.1 Pro is newer: released 2/19/2026 vs 1/13/2026.

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Related Comparisons

The Gemini 3.1 Pro and GPT-5.2 Codex comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Gemini 3.1 Pro or GPT-5.2 Codex page. See also the complete list of AI model comparisons.