Gemini 2.5 FlashvsGPT-5-Codex
Gemini 2.5 Flash | GPT-5-Codex | |
|---|---|---|
| API pricingUSD per 1M tokens · lower wins | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | $0.30 | — |
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one. | $2.50 | — |
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again. | $0.03 | — |
| Benchmarks | ||
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 19% | 39% |
| Overview | ||
| Company | OpenAI | |
| Release date | Apr 17 2025 | Sep 15 2025 |
| Access | Proprietary | Proprietary |
Other comparisons
Frequently asked questions
GPT-5-Codex leads Gemini 2.5 Flash on 1 of the 1 benchmark they both report (BullshitBench v2). Only Gemini 2.5 Flash has a verified first-party API price: $0.30 per million input tokens and $2.50 per million output tokens. No pay-as-you-go API rate is tracked for GPT-5-Codex. Gemini 2.5 Flash shipped 151 days before GPT-5-Codex, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
On BullshitBench v2, GPT-5-Codex leads at 39% vs Gemini 2.5 Flash at 19%.
Gemini 2.5 Flash was released by Google on Apr 17 2025.
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Only Gemini 2.5 Flash has a verified first-party API price: $0.30 per million input tokens and $2.50 per million output tokens. No pay-as-you-go API rate is tracked for GPT-5-Codex. Rates are pay-as-you-go API prices verified on August 18, 2026.