GPT-5.1 Medium vs GPT-5.2 Codex: Specs & Benchmark Comparison

CharacteristicGPT-5.1 MediumGPT-5.2 Codex
CompanyOpenAIOpenAI
Release DateNovember 11, 2025January 13, 2026
Parameters
MultimodalYesYes
Context (input)256K400K
Context (output)64K128K
Input Price / 1M$1.00$1.75
Output Price / 1M$4.00$14.00
Average Score1.00.6

Verdict

GPT-5.2 Codex leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5.1 Medium — 1.0, GPT-5.2 Codex — 0.6.

API Cost

GPT-5.1 Medium is 3.1x cheaper: input $1.00/1M vs $1.75/1M tokens.

Context Window

GPT-5.2 Codex supports a larger context: 400K vs 256K tokens.

Recency

GPT-5.2 Codex is newer: released 1/13/2026 vs 11/11/2025.

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Related Comparisons

The GPT-5.1 Medium 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 GPT-5.1 Medium or GPT-5.2 Codex page. See also the complete list of AI model comparisons.