Quick answer

OpenAI built ChatGPT and focuses on being first with the most capable models. Anthropic built Claude and was founded specifically to prioritise AI safety. Both are frontier AI labs with excellent models. The difference is cultural and philosophical as much as technical: OpenAI moves fast, Anthropic moves carefully.

OpenAI and Anthropic are the two companies that dominate the AI conversation in 2026. They compete on capability, but they think about AI development very differently. Here is the plain English version of what separates them.

OpenAI — speed and scale

OpenAI was founded in 2015 with a mission to ensure AI benefits all of humanity. It launched ChatGPT in November 2022, which became the fastest-growing consumer product in history. In 2026, it has over $25 billion in annual revenue. Its models — GPT-4o, GPT-5, o3 — are widely considered the most capable available. It is backed by Microsoft, which has invested over $13 billion.

Anthropic — safety first

Anthropic was founded in 2021 by former OpenAI employees — including Dario and Daniela Amodei — who left over concerns about how seriously OpenAI was taking AI safety. Its product is Claude. Its research focus is on making AI safer, more interpretable, and more reliably aligned with human values. It pioneered Constitutional AI — a method of training AI to follow a written set of principles.

How the products compare

  • ChatGPT (OpenAI) — widest user base, most integrations, best tool ecosystem
  • Claude (Anthropic) — widely preferred for writing quality and long documents, strong safety record
  • API access — both offer developer APIs; OpenAI has larger market share, Anthropic is growing fast in enterprise
  • Pricing — comparable ($20/month for consumer Pro tiers)

The philosophical difference

OpenAI believes that being at the frontier of AI capability is necessary to ensure safe outcomes — you need to be in the lead to steer the direction. Anthropic believes that slowing down to do safety work properly is worth the competitive cost. This is a genuine disagreement between smart, well-intentioned people — not a case of one being clearly right.

Funding: OpenAI has raised over $17 billion, primarily from Microsoft. Anthropic has raised over $7 billion, from Amazon ($4B) and Google ($500M). Both are well-funded enough to stay at the frontier for years.

Related reading

What Is AI Alignment and Why Does Everyone Keep Talking About It? ChatGPT vs Claude vs Gemini — Which AI Is Actually Better? What Is GPT-5 and What Can It Actually Do?

Bottom line

OpenAI and Anthropic are not enemies — they are competitors who both believe they are making AI safer by staying at the frontier. For users, the practical difference is: ChatGPT is more versatile and has more integrations, Claude is often preferred for quality writing and safety-sensitive applications. Both are worth trying.