GPT-5.3 Codex is an AI model by OpenAI. View detailed benchmark scores, pricing data, and performance metrics on Serenities AI Models.
Specifications last checked against the provider on . Benchmark scores carry their own source, linked beside each number.
Coding Benchmarks
Human preference ELO for building things — websites, UI, games, charts, SVG
Design Arena (via OpenRouter)Human preference ELO for building a working web page from a brief
Design Arena (via OpenRouter)Cost Benchmarks
Cost per 1M cached input tokens — the price that actually applies to a long agent conversation
OpenRouter APIContext Benchmarks
Available from 28 providers
The same model costs different amounts depending on who serves it. You can bring your own key for 4 of these — connect it here.
| Provider | Input / 1M | Output / 1M | Cached in | Context | Your key |
|---|---|---|---|---|---|
| Poe | $1.6 | $13 | $0.16 | 400K | — |
| Abacus | $1.75 | $14 | $0.18 | 400K | — |
| AIHubMix | $1.75 | $14 | $0.175 | 400K | — |
| Azure | $1.75 | $14 | $0.175 | 400K | Supported |
| Azure Cognitive Services | $1.75 | $14 | $0.175 | 400K | — |
| DevPass (LLM Gateway) | $1.75 | $14 | $0.175 | 400K | — |
| Eden AI | $1.75 | $14 | $0.175 | 400K | — |
| FastRouter | $1.75 | $14 | — | 400K | — |
| FreeModel | $1.75 | $14 | $0.175 | 400K | — |
| FrogBot | $1.75 | $14 | $0.175 | 400K | — |
| GitHub Copilot | $1.75 | $14 | $0.175 | 400K | — |
| Impossibl | $1.75 | $14 | $0.175 | 400K | — |
| Kilo Gateway | $1.75 | $14 | $0.175 | 400K | — |
| LLM Gateway | $1.75 | $14 | $0.175 | 400K | — |
| NanoGPT | $1.75 | $14 | $0.175 | 400K | — |
| Neon | $1.75 | $14 | $0.175 | 400K | — |
| Ofox | $1.75 | $14 | $0.18 | 400K | — |
| OpenAI | $1.75 | $14 | $0.175 | 400K | Supported |
| OpenCode Zen | $1.75 | $14 | $0.175 | 400K | — |
| OpenRouter | $1.75 | $14 | $0.175 | 400K | Supported |
| Opper | $1.75 | $14 | $0.175 | 400K | — |
| OrcaRouter | $1.75 | $14 | $0.175 | 400K | — |
| Pioneer | $1.75 | $14 | $0.175 | 400K | — |
| Requesty | $1.75 | $14 | $0.175 | 400K | — |
| Vivgrid | $1.75 | $14 | $0.175 | 400K | — |
| ZenMux | $1.75 | $14 | — | 400K | — |
| Venice AI | $2.19 | $17.5 | $0.219 | 400K | — |
| Vercel AI Gateway | $3.5 | $28 | $0.35 | 400K | Supported |
GPT-5.3 Codex — Benchmark Scores Overview
Scores normalized to percentage scale for visual comparison. ELO scores mapped to 0-100 range (1100-1500).
GPT-5.3 Codex — Frequently Asked Questions
How much does GPT-5.3 Codex cost?
GPT-5.3 Codex costs $1.8 per 1M input tokens and $14.0 per 1M output tokens. This is mid-range pricing for its capability level.
What is the context window of GPT-5.3 Codex?
GPT-5.3 Codex has a context window of 400K tokens. This determines how much text, conversation history, and code the model can process in a single request.
Who created GPT-5.3 Codex?
GPT-5.3 Codex was created by OpenAI. It is classified as a mid model in our catalogue.
Is GPT-5.3 Codex open source?
No, GPT-5.3 Codex is a proprietary model. It is available through OpenAI's API and compatible providers.