GPT-5.3 Codex — API Pricing & Benchmarks
GPT-5.3 Codex is OpenAI's mid reasoning model. The API costs $1.75 per 1M input tokens and $14.0 per 1M output tokens ($4.81 blended at a 3:1 ratio), with cached input at $0.17. It supports a 400K-token context window. On the independently measured Artificial Analysis Intelligence Index it scores 45.5, ranking #33 of 68 models tracked on this site, with a median output speed of 126 tokens/sec.
Explore provider routes and additional benchmark sources for GPT-5.3 Codex
| Provider | OpenAI |
| Input price / 1M tokens | $1.75 |
| Output price / 1M tokens | $14.0 |
| Cached input / 1M tokens | $0.17 |
| Blended price (3:1) | $4.81 |
| Context window | 400K |
| Max output tokens | 128K |
| Knowledge cutoff | 2025-08 |
| License | proprietary |
| Input modalities | T+I |
| Output speed (tok/s) | 126 |
| Released | — |
| Artificial Analysis Intelligence Index | 45.5 |
| GPQA Diamond | 91.5% |
| SWE-bench Verified | 85% |
| Humanity's Last Exam | 42.5% |
Where GPT-5.3 Codex fits
On a blended 3:1 basis GPT-5.3 Codex costs $4.81 per 1M tokens, cheaper than 20% of the 80 priced models in this index. It sits in the mid-tier bracket where most production chat, RAG and summarization workloads run: meaningfully cheaper than flagships while keeping most of their capability. Cached input is priced at $0.17 (90% below standard input), which rewards prompt structures with long stable prefixes — see our caching guide.
Price history
| Period | Input $/1M | Output $/1M | Cached $/1M |
|---|---|---|---|
| 2026-07-18 → current | $1.75 | $14.0 | $0.17 |
No list-price changes recorded since tracking began. Full dataset: price-history.json (CC BY 4.0).
Alternatives at a similar price
- GPT-5.6 Terra (OpenAI) — $4.50/1M blended, AA Index 56.6
- Gemini 3.1 Pro (Google) — $4.50/1M blended, AA Index 47.7
- GPT-4o (OpenAI) — $4.38/1M blended, AA Index 12.3
- Command A (Cohere) — $4.38/1M blended, AA Index 7.5
About OpenAI
OpenAI builds the GPT series. GPT-6 Astra (September 2026) sits at the top at $10/$50, and beneath it the GPT-5.6 generation ships in three sizes — Sol, Terra and Luna — that share the same 1.05M-token context window and tooling, so teams can move workloads between price points without changing integration code.