GPT-5.3 Codex Spark vs Kimi K3
Price and specs side by side · USD per 1M tokens · verified 2026-10-11
// side by side
| metric | GPT-5.3 Codex Spark | Kimi K3 |
|---|
| input / 1M | $1.75 | $3.00 |
| output / 1M | $14.00 | $15.00 |
| blended (3:1) | $4.8125 | $6.00 |
| cache read / 1M | $0.175 | $0.30 |
| context | 128K | 1.05M |
| max output | 32K | 1.05M |
| input types | text · image · pdf | text · image · video |
| reasoning | yes | yes |
| tool calling | yes | yes |
| structured output | yes | yes |
| open weights | no | yes |
| released | 2026-02-05 | 2026-07-16 |
| knowledge cutoff | 2025-08-31 | n/a |
| lab | OpenAI | Moonshot AI |
// monthly cost scenarios
| workload | tokens in / out | GPT-5.3 Codex Spark | Kimi K3 |
|---|
| Chatbot | 10M / 2M | $45.50 | $60.00 |
| RAG app | 50M / 5M | $158 | $225 |
| Coding agent | 20M / 10M | $175 | $210 |
// verdict
- GPT-5.3 Codex Spark is 19.8% cheaper than Kimi K3 on a blended 3:1 input/output basis.
- Kimi K3 has the larger context window (1.05M vs 128K tokens).