GPT-5 Medium vs GPT-5.1 Codex High: Specs & Benchmark Comparison
| Characteristic | GPT-5 Medium | GPT-5.1 Codex High |
|---|---|---|
| Company | OpenAI | OpenAI |
| Release Date | August 6, 2025 | November 11, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 400K | 400K |
| Context (output) | 64K | 128K |
| Input Price / 1M | $0.75 | $1.25 |
| Output Price / 1M | $3.00 | $10.00 |
| Average Score | 0.9 | 1.0 |
| Benchmarks | ||
| AIME 2025 | 0.9 | 1.0 |
Visual Benchmark Comparison
GPT-5 Medium
GPT-5.1 Codex High
AIME 20250.9 vs 1.0
0.9
1.0
Verdict
Both models show equal results — the choice depends on your specific use case.
Overall Performance
Both models show comparable average scores: GPT-5 Medium — 0.9, GPT-5.1 Codex High — 1.0.
API Cost
GPT-5 Medium is 3.0x cheaper: input $0.75/1M vs $1.25/1M tokens.
Context Window
Same context size: 400K tokens.
Recency
GPT-5.1 Codex High is newer: released 11/11/2025 vs 8/6/2025.
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The GPT-5 Medium and GPT-5.1 Codex High 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 Medium or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.