GPT-4o

entitystableCreated: 2026-07-24Updated: 2026-07-24Source: openai.com/index/hello-gpt-4o/
openaiclosed-sourcemultimodaltext-generationvisionlong-context

GPT-4o

GPT-4o ("omni") is OpenAI's flagship multimodal model, released in May 2024. It unifies vision, audio, and text understanding in a single end-to-end trained model.

Key Specifications

  • Context window: 128K tokens
  • Max output tokens: 16,384
  • Training data cutoff: October 2023 (GPT-4o), June 2024 (GPT-4o-2024-08-06)
  • Architecture: Transformer (proprietary)
  • Modalities: Text, image, audio input; text output (audio in API)
  • Pricing: $2.50 / $10.00 per 1M input/output tokens (GPT-4o); $10.00 / $30.00 (GPT-4o-2024-05-13)

Capabilities

  • Multimodal understanding — Processes images, screenshots, documents with text
  • Vision — Scene understanding, OCR, diagram reading, chart analysis
  • Function calling — Native tool use support
  • structured-output — JSON mode with schema validation
  • Vision + reasoning — Can analyze images and explain reasoning

Architecture Notes

GPT-4o is a decoder-only transformer with multi-head-attention. It uses GQA for efficient inference. The model was trained with a novel multimodality approach where vision, audio, and text are processed by a single neural network rather than separate specialized modules.

Benchmarks

Benchmark Score
MMLU 88.7%
HumanEval 90.2%
GSM8K 96.1%
MATH 76.6%

Comparison

See LLM API Pricing Comparison for cost comparison across models. See Open-Source vs Closed-Source LLMs for the broader open vs closed landscape.

Related

  • o1 — OpenAI's reasoning model
  • gpt-4o-mini — Smaller, cheaper variant
  • Claude 4 — Direct competitor from Anthropic
  • Gemini 2 Pro — Direct competitor from Google