GPT-5.3-Codex
OpenAI • codigo
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...
Specifications
Context Window
400K tokens
Input Price/1M
$1.75
Output Price/1M
$14.00
Parameters
—
Speed
85 tok/s
Latency (TTFT)
54.0s
Max Output
128K tokens
Benchmarks
GPT-5.3-Codex results on the main AI model evaluation benchmarks. Higher scores indicate better performance.
Agentic
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| Terminal-Bench Hard | 53.0 | 100.0 | — |
Coding
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA Coding Index | 53.1 | 100.0 | Artificial Analysis official API |
| SciCode | 53.0 | 100.0 | — |
Long Context
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA-LCR | 74.0 | 100.0 | — |
overall
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA Intelligence Index | 53.6 | 100.0 | Artificial Analysis official API |
Reasoning
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| GPQA Diamond | 92.0 | 100.0 | Artificial Analysis official API |
| IFBench | 75.0 | 100.0 | — |
| HLE | 40.0 | 100.0 | — |
Tool Use
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| Tau²-Bench | 86.0 | 100.0 | — |
Information
- Release date
- February 05, 2026
- Tool Calling
- ✅ Supported
- Vision
- ✅ Supported
- Audio
- ❌ Not supported
Full Analysis: GPT-5.3-Codex
What is GPT-5.3-Codex?
GPT-5.3-Codex is an AI model developed by OpenAI, classified as a codigo model. It is a multimodal model, capable of processing text, images, and potentially other media types. As a proprietary model, it is available via OpenAI's cloud API. With a context window of 400K tokens, it is suitable for processing long documents such as contracts, books, and complete codebases.
Pricing & Costs in 2026
GPT-5.3-Codex is usage-based, priced at $1.75/1M input tokens and $14/1M output tokens. For context: 1 million tokens is approximately 750,000 words, or about 10 average-length books. The mid-range pricing balances quality and cost for most professional applications.
Benchmarks & Performance
GPT-5.3-Codex was evaluated on 9 different benchmarks, covering categories like Agentic, Coding, Long Context, overall, Reasoning, Tool Use. Results show exceptional performance across available evaluations.
It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.
Recommended Use Cases
GPT-5.3-Codex specializes in codigo, offering advanced capabilities for creating and processing codigo content.
Comparison with Alternatives
In the 2026 AI model ecosystem, GPT-5.3-Codex competes directly with similarly capable models. Key competitors include Claude (Anthropic), Gemini (Google), and open source models like Llama (Meta) and Qwen (Alibaba). The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.
For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.
Frequently Asked Questions
What is 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...
How much does GPT-5.3-Codex cost?
GPT-5.3-Codex costs $1.75/1M input tokens and $14/1M output tokens. For heavy usage (e.g., a chatbot handling 100k messages/month), costs can range from $10 to $1,000 depending on volume.
How does GPT-5.3-Codex compare with other models?
In available benchmarks, GPT-5.3-Codex scored: Terminal-Bench Hard: 53/100, AA Coding Index: 53.1/100, SciCode: 53/100. See the full table above for a detailed comparison.
Is GPT-5.3-Codex open source?
No, GPT-5.3-Codex is a proprietary model from OpenAI. It is available via cloud API. For open source alternatives, check our open source model ranking.
What is GPT-5.3-Codex best for?
GPT-5.3-Codex excels at complex reasoning and problem solving. With its large context window, it handles long documents, codebases, and extended conversations. It supports tool calling for API integrations and automation.
Last updated: June 01, 2026 • View methodology →