Curiosity · AI Model
GPT-4 Turbo
GPT-4 Turbo was OpenAI's mid-cycle upgrade to the original GPT-4, shipping with a 128K-token context window, function calling, JSON-mode outputs, and optional vision via gpt-4-turbo-vision. It drove the first wave of serious enterprise GPT-4 deployments in 2024 and is still reachable via the legacy endpoints today.
Model specs
- Vendor
- OpenAI
- Family
- GPT-4
- Released
- 2023-11
- Context window
- 128,000 tokens
- Modalities
- text, vision
- Input price
- $10/M tok
- Output price
- $30/M tok
- Pricing as of
- 2026-04-20
Strengths
- Reliable JSON-mode structured outputs
- Mature ecosystem — most tools support gpt-4-turbo out of the box
- Broadly available via Azure OpenAI with strict SLA
Limitations
- Outperformed by GPT-4o on latency, multimodal, and price
- No native audio, weaker vision than gpt-4o
- OpenAI considers it legacy — new features target the -o and -5 families
Use cases
- Legacy enterprise chatbots built on the GPT-4 era
- Long-document RAG pipelines using 128K context
- Structured-output generation via JSON mode
- Function-calling agent loops from the 2024 stack
Benchmarks
| Benchmark | Score | As of |
|---|---|---|
| MMLU | ≈86% | 2024-01 |
| HumanEval | ≈87% | 2024-01 |
| MATH | ≈52% | 2024-01 |
Frequently asked questions
What is GPT-4 Turbo?
GPT-4 Turbo is OpenAI's November 2023 upgrade to GPT-4, offering a 128K-token context window, JSON-mode structured output, function calling, and optional vision input at a meaningfully lower price than the original GPT-4 model.
Is GPT-4 Turbo still supported?
Yes — OpenAI continues to host GPT-4 Turbo endpoints for enterprise customers who depend on its behavior, though newer workloads should target GPT-4o or GPT-5 for better latency and pricing.
What is the context window of GPT-4 Turbo?
GPT-4 Turbo supports a 128,000-token context window with up to 4,096 output tokens per completion.
Should I migrate off GPT-4 Turbo?
Most new projects should target GPT-4o or GPT-5 mini for equal or better capability at lower cost and latency. Migrate when you can re-test prompts and structured outputs.
Sources
- OpenAI — GPT-4 and GPT-4 Turbo — accessed 2026-04-20
- OpenAI — DevDay 2023 announcement — accessed 2026-04-20