OpenAI
GPT-5.3 Codex
OpenAI's February 5, 2026 agentic coding model for building, debugging and maintaining software. At launch, OpenAI reported 56.8% on SWE-Bench Pro (Public) with xhigh reasoning effort. Accepts text and images and produces text, with a 400K-token context window, up to 128K output tokens and low, medium, high or xhigh reasoning effort.
400K tokens
Multimodal
Max
- Provider
- OpenAI
- Context
- 400KCatalog · As of Aug 11, 2026Stale · 31d old
- yno subscription tier
- Max
- Released
- Feb 5, 2026
- Speed
- Medium
- Reasoning
- Expert
- Modality
- Multimodal
Benchmarks
Quality
- AA Intelligence Index
- GPQA Diamond
- 91.5%Artificial Analysis · Date unknownAge unknown
Speed and latency
- Output speed
- 136.31tokens/sConfiguration: Prompt length: 1,000 · Parallel queries: 1Artificial Analysis · Date unknownAge unknown
- Time to first token
- 45.91sConfiguration: Prompt length: 1,000 · Parallel queries: 1Artificial Analysis · Date unknownAge unknown
- Time to first answer token
- 45.91sConfiguration: Prompt length: 1,000 · Parallel queries: 1Artificial Analysis · Date unknownAge unknown
API pricing
- API input cost
- API output cost
Benchmark variant: GPT-5.3 Codex (xhigh)
AA data retrieved Sep 11, 2026 · Artificial Analysis
Indexes use points; evaluations use accuracy percentages. API measurements do not measure yno application performance. Methodology
Capabilities
- Code
- Agentic Coding
- Debugging
- Refactoring
- Tool Use
- Vision
Use cases
- Autonomous coding agents
- Large-scale refactoring
- CI/CD automation
- Code review
Strengths
- SWE-Bench Pro (Public) 56.8% at launch, xhigh
- 400K context / 128K output
- Text and image input
- Agentic coding
Best for
Engineering teams building autonomous coding pipelines and CI/CD agents
Use GPT-5.3 Codex in yno.ai
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Related models
Frequently asked
- What is GPT-5.3 Codex?
- OpenAI's February 5, 2026 agentic coding model for building, debugging and maintaining software. At launch, OpenAI reported 56.8% on SWE-Bench Pro (Public) with xhigh reasoning effort. Accepts text and images and produces text, with a 400K-token context window, up to 128K output tokens and low, medium, high or xhigh reasoning effort.
- How much does GPT-5.3 Codex cost in yno.ai?
- GPT-5.3 Codex is available on the Max tier of yno.ai.
- What can GPT-5.3 Codex do?
- GPT-5.3 Codex is best for Engineering teams building autonomous coding pipelines and CI/CD agents. Its main capabilities include Code, Agentic Coding, Debugging, Refactoring, Tool Use, Vision.
- How does GPT-5.3 Codex compare to other models?
- GPT-5.3 Codex excels at SWE-Bench Pro (Public) 56.8% at launch, xhigh and is recommended for Autonomous coding agents, Large-scale refactoring, CI/CD automation, Code review. See related models below.
- How do I use GPT-5.3 Codex in yno.ai?
- Sign up for yno.ai, select GPT-5.3 Codex from the model picker, and start chatting.