Free Tier
$0
- $100 monthly spending cap
- Basic rate limits
- Access to GPT-3.5 Turbo
OpenAI: Foundation Models
Founded 2015|San Francisco, California|1001-5000 people|Usage-based
What is OpenAI?
OpenAI is the creator of ChatGPT and the GPT series of large language models, having pioneered the commercial LLM API market. Founded in December 2015 by Sam Altman, Elon Musk, Greg Brockman, Ilya Sutskever, and others as a non-profit, it transitioned to a capped-profit model in 2019 and is currently restructuring as a for-profit public benefit corporation.
OpenAI's API platform provides access to text generation (GPT-4o, GPT-5, o-series reasoning models), image generation (DALL-E), speech-to-text (Whisper), text-to-speech, and embedding models. The platform supports fine-tuning, function calling, and the Responses API for agent-native workflows. The open-source Agents SDK and tools like code interpreter and web search enable developers to build sophisticated AI applications.
In February 2026, OpenAI closed a record $110 billion funding round from Amazon, Nvidia, and SoftBank, valuing the company at $840 billion post-money. The company employs approximately 3,500-7,200 people and is reportedly targeting a 2027 IPO at up to a $1 trillion valuation.
Key features
Core capabilities this platform advertises.
- GPT-4o and GPT-4 Turbo frontier models
- Function calling and structured outputs
- Fine-tuning API
- DALL-E image generation
- Whisper speech-to-text
Strengths and tradeoffs
What this tool does well, and the limitations to keep in mind.
Pros
- Broadest range of AI models under one API (text, reasoning, image, audio)
- Well-documented API with simple SDKs and minimal learning curve
- State-of-the-art model quality across GPT and o-series reasoning models
- Fastest path from idea to working prototype with agent-native APIs
- API inputs not used for model training by default
Cons
- High cost at scale, especially for output-heavy workloads
- Vendor lock-in to OpenAI ecosystem and tooling
- History of API deprecations creating migration risk
- Data privacy and transparency concerns for regulated industries
Plans & pricing
What's included in each plan, and how the tiers compare.
Tier 1
Pay-as-you-go
- $5+ spend to qualify
- $100 monthly cap
- GPT-4o at $2.50/$10 per 1M tokens
Tier 2-4
Pay-as-you-go
- $50-$250+ spend to qualify
- Up to $5,000 monthly cap
- Higher rate limits
Tier 5
Pay-as-you-go
- $1,000+ spend to qualify
- $200,000 monthly cap
- Maximum rate limits
Common use cases
Developers and enterprises building AI-powered applications across all industries
- General-purpose text generation and chat
- Code generation and debugging
- Content creation and summarization
- Multi-modal applications with vision and audio
- Enterprise knowledge assistants
Using OpenAI with Respan
Respan acts as a unified gateway for OpenAI API calls, providing real-time observability, cost tracking, and intelligent routing. Teams can monitor token usage, latency, and error rates across all OpenAI models while enabling automatic fallback to alternative providers when OpenAI experiences outages.
- Real-time cost tracking across all OpenAI models
- Automatic fallback routing when OpenAI is down
- Compare OpenAI model performance against alternatives
- Cache repeated queries to reduce OpenAI API costs
Run OpenAI in production with Respan
10KFree traces/mo
1,000+Models
5 minSetup
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan freeBest OpenAI alternatives & competitors
Top companies in Foundation Models you can use instead of OpenAI.
Anthropic
Claude 4 and Claude 3.5 Sonnet models
Google AI
Gemini 2.0 multimodal models
Meta AI
Llama open-source model family
Mistral AI
Mistral Large and Mixtral models
Voyage AI (MongoDB)
Text & multimodal embeddings
Cohere
Command R+ for RAG applications
Microsoft
Small language models
xAI
Grok models with real-time data access
DeepSeek
DeepSeek-V3 and DeepSeek-R1 models
Databricks (DBRX)
Moonshot AI
Black Forest Labs
Image generation
Alibaba Qwen
Qwen2 open-source model series
Snowflake
Arctic models
Stability AI
Stable Diffusion image generation
Reka
01.AI
Zhipu AI
Guide Labs
Inherently interpretable LLM architecture
Cascade
Model distillation
Luel
Natural language to training data
OpenAI models and API status
Live API status, the current flagship model and how OpenAI's models compare, from the Respan model hub.
Compare OpenAI
Side-by-side comparisons with other tools in this category.
Best integrations for OpenAI
Companies from adjacent layers in the AI stack that work well with OpenAI.
Last verified: February 28, 2026