Anthropic: Foundation Models

Founded 2021|San Francisco, California|1001-5000 people|Usage-based

What is Anthropic?

Anthropic is an AI safety and research company that builds the Claude family of large language models. Founded in 2021 by Dario Amodei (CEO) and Daniela Amodei (President), along with five other former OpenAI employees, the company is structured as a Public Benefit Corporation with a Long-Term Benefit Trust to prioritize societal benefit.

Claude models are known for strong reasoning capabilities, large context windows (up to 200K tokens), and an emphasis on safety and reliability. Claude Sonnet 4.5 leads as the top coding model with 77.2% on SWE-bench Verified, while the three-tier pricing system (Haiku, Sonnet, Opus) provides flexibility for different use cases. Anthropic pioneered Constitutional AI and created the Model Context Protocol (MCP), now an industry standard for AI tool integration donated to the Linux Foundation.

The company serves enterprise customers through both its API platform and the Claude.ai consumer product. Claude has grown from 2.9 million monthly users in January 2024 to 18.9 million by early 2025, with $850 million in annualized revenue. As of February 2026, Anthropic is valued at approximately $380 billion and employs roughly 2,000-4,000 people across its San Francisco headquarters.

Key features

Core capabilities this platform advertises.

Claude 4 and Claude 3.5 Sonnet models
200K token context window
Computer use and tool use capabilities
Strong safety and instruction following
Claude Code for autonomous coding

Strengths and tradeoffs

What this tool does well, and the limitations to keep in mind.

Pros

Industry-leading instruction-following and reasoning capabilities
Top-ranked coding model (Sonnet 4.5 at 77.2% SWE-bench)
Large 200K context window for long-document analysis
Strong safety focus with lower hallucination rates
Flexible three-tier pricing from $1 to $75 per MTok

Cons

No native image generation capabilities
Smaller training corpus than some competitors
Ecosystem integration less mature than OpenAI
Limited public transparency about model updates and version changes

Plans & pricing

What's included in each plan, and how the tiers compare.

Haiku 4.5

$1/$5 per MTok (input/output)

Fastest model
Best for high-volume tasks
Low-latency responses

Sonnet 4.5

$3/$15 per MTok (input/output)

Best coding model
Balanced performance and cost
200K context window

Opus 4.6

$15/$75 per MTok (input/output)

Most capable model
Complex reasoning tasks
Extended thinking

View official pricing page

Common use cases

Developers and enterprises who need reliable, safe, and capable AI for production applications

Long document analysis and summarization
Complex reasoning and research tasks
Autonomous coding and software engineering
Safe customer-facing AI applications
Enterprise workflow automation

Using Anthropic with Respan

Respan provides a unified gateway for Anthropic Claude API calls alongside 250+ other LLMs. Teams can route requests through Respan to monitor Claude usage, compare model performance, and enable automatic fallback between Claude and other providers for maximum reliability.

Monitor Claude API costs and usage in real-time
Enable automatic fallback between Claude models and alternatives
Compare Claude performance against competing models
Cache repeated Claude queries to reduce costs by up to 70%

Run Anthropic in production with Respan

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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.

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Best Anthropic alternatives & competitors

Top companies in Foundation Models you can use instead of Anthropic.

OpenAI

GPT-4o and GPT-4 Turbo frontier models