OpenAI: GPT-5.3-Codex
Analysis Summary
OpenAI: GPT-5.3-Codex sits in the Frontier tier on our leaderboard, ranked #4 of 523 published models on overall intelligence. At $1.75 input and $14.00 output per 1M tokens, it is among the most expensive on the market. It offers a generous context window for extended reasoning and code review and supports tool use, function calling, vision, and reasoning.
Editorial notes
OpenAI's GPT-5.3-Codex is a world-class coding and reasoning model with outstanding performance across intelligence, coding, and agentic benchmarks, vision support, and a 400K context window ā one of the strongest choices available for technically demanding business workflows.
Assessed April 16, 2026
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
Performance Profile
GPT-5.3-Codex is OpenAIās 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..
Capabilities
Performance Indices
Source: Artificial Analysis
Benchmark Scores
Intelligence
Technical
Content
Benchmark data from Artificial Analysis and Hugging Face
How does OpenAI: GPT-5.3-Codex stack up?
Compare side-by-side with other frontier models.
Model Information
| OpenRouter ID |
openai/gpt-5.3-codex
|
| Provider | openai |
| Release Date | February 24, 2026 |
| Context Length | 400,000 tokens |
| Max Completion | 128,000 tokens |
| Status | Active |
Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $1.75 | $0.001750 |
| Output | $14.00 | $0.014000 |
Live Performance
Live endpoint metrics ā refreshed every 30 minutes.
