GPT-5.1 Codex High vs GPT-5.4: Specs & Benchmark Comparison

CharacteristicGPT-5.1 Codex HighGPT-5.4
CompanyOpenAIOpenAI
Release DateNovember 11, 2025March 5, 2026
Parameters
MultimodalYesYes
Context (input)400K1.0M
Context (output)128K128K
Input Price / 1M$1.25$2.50
Output Price / 1M$10.00$15.00
Average Score1.00.9

Verdict

GPT-5.4 leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5.1 Codex High — 1.0, GPT-5.4 — 0.9.

API Cost

GPT-5.1 Codex High is 1.6x cheaper: input $1.25/1M vs $2.50/1M tokens.

Context Window

GPT-5.4 supports a larger context: 1M vs 400K tokens.

Recency

GPT-5.4 is newer: released 3/5/2026 vs 11/11/2025.

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Related Comparisons

The GPT-5.1 Codex High and GPT-5.4 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 Codex High or GPT-5.4 page. See also the complete list of AI model comparisons.