Chat / reasoning
GPT flagship models
Best for: Hard problems, writing, coding, analysis
The main models behind ChatGPT; newer generations can “think longer” automatically on difficult tasks.
AppAPI
🇺🇸 United States · USA
OpenAI models explained
OpenAI makes ChatGPT and offers its models to developers through an API. Its line-up spans flagship GPT models with built-in reasoning, smaller low-cost versions, open-weight models, and dedicated image, video and audio models.
All model families
Chat (fast / low cost)
GPT mini & nano sizes
Best for: High-volume apps, quick tasks
Cheaper and faster versions for developers building products at scale.
AppAPI
Reasoning
o-series reasoning models
Best for: Maths, science, multi-step logic
Models trained to reason step by step before answering; reasoning is increasingly merged into the flagship GPT line.
AppAPI
Open-weight chat / reasoning
gpt-oss
Best for: Running OpenAI-made models on your own hardware
OpenAI’s open-weight models, available through Hugging Face, Ollama and LM Studio.
Open weights
Image generation & editing
GPT image models
Best for: Images from chat, text in images, edits
Powers image creation inside ChatGPT.
AppAPI
Video generation
Sora
Best for: Short videos from text or images
Available through the Sora app and website.
App
Speech-to-text / text-to-speech
Whisper & speech models
Best for: Transcription, voice apps
Whisper is open-source; newer speech and real-time voice models are available via the API.
APIOpen weights
Search / retrieval
Embeddings
Best for: Semantic search, RAG
Turn text into vectors for search and recommendation.
API
Model names and versions change often. Check the official documentation for the newest releases.
⚡ Which model should you use?
- Everyday use: just use ChatGPT — it picks the model for you.
- Building an app: start with a mini model and move up only if quality is not enough.
- Need privacy / offline: run gpt-oss locally with Ollama or LM Studio.
Data, privacy and your region
US providers offer business and enterprise plans with data-processing agreements, and some offer regional data residency (including in the EU/UK). Check the plan’s data-use and retention settings before sharing sensitive information.
Frequently asked questions
Which OpenAI model is the best?
The latest flagship GPT model is the most capable; for most apps a smaller mini model offers the best balance of cost and quality.
Does OpenAI have open-source models?
Yes — gpt-oss is released with open weights, and Whisper (speech-to-text) is open-source.