GPT-5.3-Codex vs GPT-5 Chat
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.3-Codex and GPT-5 Chat.
GPT-5.3-Codex
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...
GPT-5 Chat
GPT-5 Chat is designed for advanced, natural, multimodal, and context-aware conversations for enterprise applications.
Technical Specifications
| Specification | GPT-5.3-Codex | GPT-5 Chat |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 400,000 tokens | 128,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2026-02-24 | 2025-08-07 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.3-Codex
$1.75
GPT-5 Chat
$1.25
Output Price per Million Tokens
GPT-5.3-Codex
$14.00
GPT-5 Chat
$10.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.3-Codex Quirks & Gotchas
No developer gotchas reported.
GPT-5 Chat Quirks & Gotchas
No developer gotchas reported.