OpenAI: GPT-5.3-Codex
GPT-5.3-Codex is a paid model from OpenAI that accepts text, images, and files as input, giving it a reasonably broad multimodal reach. Its 400,000-token context window accommodates long documents and extended conversations, and it supports both tool use and reasoning, which makes it suitable for multi-step tasks and agentic workflows. Structured output support is unconfirmed based on available data. On pricing, $1.75 per million input tokens is competitive, but the $14.00 per million output tokens is on the higher end and will add up quickly in output-heavy workloads. Its blended benchmark score of 73.4 rests on coverage from a single benchmark, so treat that figure as a limited signal rather than a broad endorsement. Teams running document-heavy or tool-augmented pipelines may find the context and reasoning support worthwhile, but cost-sensitive users should model their expected output volume carefully before committing.
- Model ID
- openai/gpt-5.3-codex
- Vendor
- openai
- Tokenizer
- GPT
- Input Modalities
- text, image, file
- Output Modalities
- text
- Max Output
- 128,000 tokens
- Tool Calling
- ✓ supported
- Structured Output
- ✓ supported
- Reasoning Mode
- ✓ supported
- Vision
- ✓ accepts images
- Audio
- no
- Moderated
- yes