Gemini 3.6 Flash vs GPT-5.1 Codex High: Specs & Benchmark Comparison
Gemini 3.6 Flash is developed by Google, while GPT-5.1 Codex High comes from OpenAI. GPT-5.1 Codex High was released in November 2025, and Gemini 3.6 Flash followed 8 months later in July 2026.
We have 7 benchmark results for Gemini 3.6 Flash and 1 benchmark result for GPT-5.1 Codex High, but they were measured on different benchmarks, so there is no like-for-like scoreboard.
GPT-5.1 Codex High is the cheaper API at $1.25 per million input tokens and $10 per million output tokens, about 20% below Gemini 3.6 Flash at $1.50 and $7.50. Gemini 3.6 Flash takes the larger context window at 1M tokens, compared with 400K for GPT-5.1 Codex High. Both accept text and images as input.
| Characteristic | Gemini 3.6 Flash | GPT-5.1 Codex High |
|---|---|---|
| Company | OpenAI | |
| Release Date | July 21, 2026 | November 11, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 400K |
| Context (output) | 66K | 128K |
| Input Price / 1M | $1.50 | $1.25 |
| Output Price / 1M | $7.50 | $10.00 |
| Average Score | 68.0% | 97.0% |
Verdict
Gemini 3.6 Flash leads in 3 out of 4 comparison categories.
Both models show comparable average scores: Gemini 3.6 Flash — 0.7, GPT-5.1 Codex High — 1.0.
Gemini 3.6 Flash is 1.3x cheaper: input $1.50/1M vs $1.25/1M tokens.
Gemini 3.6 Flash supports a larger context: 1M vs 400K tokens.
Gemini 3.6 Flash is newer: released 7/21/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — Gemini 3.6 Flash or GPT-5.1 Codex High?
Which model is cheaper — Gemini 3.6 Flash or GPT-5.1 Codex High?
Which has a larger context window — Gemini 3.6 Flash or GPT-5.1 Codex High?
The Gemini 3.6 Flash 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 Gemini 3.6 Flash or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.