GPT-5.1-Codex vs GPT-5.4
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.1-Codex and GPT-5.4.
GPT-5.1-Codex
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....
GPT-5.4
GPT-5.4 is OpenAI’s latest frontier model, unifying the Codex and GPT lines into a single system. It features a 1M+ token context window (922K input, 128K output) with support for...
Technical Specifications
| Specification | GPT-5.1-Codex | GPT-5.4 |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 400,000 tokens | 1,050,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | beta |
| API Available | Yes | Yes |
| Released Date | 2025-11-13 | 2026-03-05 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.1-Codex
$1.25
GPT-5.4
$2.50
Output Price per Million Tokens
GPT-5.1-Codex
$10.00
GPT-5.4
$15.00
Want to test both models live?
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.1-Codex Quirks & Gotchas
No developer gotchas reported.
GPT-5.4 Quirks & Gotchas
No developer gotchas reported.