LLM API
OpenAIText generationReleased February 5, 2026Deprecated

GPT-5.3 Codex

GPT-5.3 Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens on LLM API, with a 400K-token context window.

Pricing

Lowest price among 2 providers, after discounts.

GPT-5.3 Codex prices on LLM API
Input$1.75per 1M tokens
Output$14per 1M tokens
Cache read$0.175per 1M tokens
Web search$0.01per search

Providers

Prices after each provider’s discount; the lowest in bold.

Providers of GPT-5.3 Codex on LLM API
Azure$1.75$14$0.175400K4K
OpenAI$1.75$14$0.175400K4K

Features

  • ToolsYes
  • Parallel tool callsNo
  • Image inputYes
  • ReasoningYes

    Levels: none, low, medium, high

  • Prompt cachingYes
  • Structured outputsYes
  • JSON modeYes
  • StreamingYes
  • Web searchYes
  • Also acceptscodex-mini-latest

Call GPT-5.3 Codex

POST /v1/responsesSet LLMAPI_KEY to your LLM API key.Responses docs

import os

from openai import OpenAI

client = OpenAI(
    base_url="https://api.llmapi.ai/v1",
    api_key=os.environ["LLMAPI_KEY"],
)

response = client.responses.create(
    model="gpt-5.3-codex",
    input="Hello",
)
print(response.output_text)

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