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

CharacteristicGPT-5.1 ThinkingGPT-5.2 Codex
CompanyOpenAIOpenAI
Release DateNovember 11, 2025January 13, 2026
Parameters
MultimodalYesYes
Context (input)256K400K
Context (output)128K128K
Input Price / 1M$3.00$1.75
Output Price / 1M$12.00$14.00
Average Score0.90.6

Verdict

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

Overall Performance

Both models show comparable average scores: GPT-5.1 Thinking — 0.9, GPT-5.2 Codex — 0.6.

API Cost

GPT-5.1 Thinking is 1.1x cheaper: input $3.00/1M 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.

More About These Models

Related Comparisons

Frequently Asked Questions

Which is better for coding — GPT-5.1 Thinking or GPT-5.2 Codex?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GPT-5.1 Thinking or GPT-5.2 Codex?
GPT-5.2 Codex is cheaper for input: $1.75 per 1M tokens vs $3.00.
Which has a larger context window — GPT-5.1 Thinking or GPT-5.2 Codex?
GPT-5.2 Codex supports a larger context: 400,000 tokens vs 256,000.

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