Gemini 3.1 Pro Preview Custom Tools vs GPT-5.3 Codex Spark
Price and specs side by side · USD per 1M tokens · verified 2026-10-11
// side by side
| metric | Gemini 3.1 Pro Preview Custom Tools | GPT-5.3 Codex Spark |
|---|---|---|
| input / 1M | $2.00 | $1.75 |
| output / 1M | $12.00 | $14.00 |
| blended (3:1) | $4.50 | $4.8125 |
| cache read / 1M | $0.20 | $0.175 |
| context | 1.05M | 128K |
| max output | 65.5K | 32K |
| input types | text · image · video · audio · pdf | text · image · pdf |
| reasoning | yes | yes |
| tool calling | yes | yes |
| structured output | yes | yes |
| open weights | no | no |
| released | 2026-02-19 | 2026-02-05 |
| knowledge cutoff | 2025-01 | 2025-08-31 |
| lab | OpenAI |
// monthly cost scenarios
| workload | tokens in / out | Gemini 3.1 Pro Preview Custom Tools | GPT-5.3 Codex Spark |
|---|---|---|---|
| Chatbot | 10M / 2M | $44.00 | $45.50 |
| RAG app | 50M / 5M | $160 | $158 |
| Coding agent | 20M / 10M | $160 | $175 |
// verdict
- Gemini 3.1 Pro Preview Custom Tools is 6.5% cheaper than GPT-5.3 Codex Spark on a blended 3:1 input/output basis.
- Gemini 3.1 Pro Preview Custom Tools has the larger context window (1.05M vs 128K tokens).