# GPT-5.3-Codex: AI model fact sheet

- **Provider:** openai
- **Released:** 2026-02-24
- **Context window:** 400,000 tokens
- **API pricing:** $1.75 / 1M input, $14.00 / 1M output
- **OpenRouter ID:** openai/gpt-5.3-codex
- **Capabilities:** conversation, reasoning, code-generation, analysis, agentic-tool-use

GPT-5.3-Codex is OpenAI's most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results on SWE-Bench Pro and strong performance on Terminal-Bench 2.0 and OSWorld-Verified, reflecting improved multi-language coding, terminal proficiency, and real-world computer-use skills. The model is optimized for long-running, tool-using workflows and supports interactive steering during execution, making it suitable for complex development tasks, debugging, deployment, and iterative product work.

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/gpt-5.3-codex