How it works
Claude models come in tiers: Haiku for fast, low-cost work, Sonnet as the balanced middle, and Opus and larger tiers for demanding reasoning and long-running agent tasks. They read text, images and PDFs, and recent models take up to about a million tokens of context at the standard rate. The Messages API supports tool use, structured outputs, citations, web search, code execution and computer use (operating a browser or desktop on the user's behalf).
There is no free API tier: you buy credit in the Claude Console and pay per token. Prompt caching makes repeated long prompts much cheaper (a cache hit costs a tenth of the normal input price or less), and the Batch API halves prices for work that can wait. Anthropic does not train on commercial API data by default. The models are also sold through Amazon Bedrock, Google Cloud and Microsoft Foundry, and Anthropic created MCP, which its apps and SDKs support closely.
Claude API pros and cons
Pros
- Strong at code, long documents and multi-step agent work
- Large context windows at the standard per-token rate
- Prompt caching and batch discounts cut the cost of repeated work
- Available directly or through AWS, Google Cloud and Microsoft Foundry
Cons
- No free API tier; every call is paid
- No embedding model of its own, so vector search needs another provider
- Tool-heavy agent runs use many tokens and add up quickly
When to use Claude API
Pick it when
- Coding assistants, agents and long multi-step tasks
- Long documents, contracts or codebases in a single prompt
- You want MCP tool connections to work with little glue code
Skip it when
- You need a free tier to prototype (Gemini offers one)
- Simple high-volume tasks where a cheaper small model does the job
Claude API pricing
Pay as you go
Per million tokens: from about $1 input and $5 output (Haiku) to about $10 input and $50 output for the largest models. Batch jobs are half price.
Claude API pricing page (opens in a new tab)Approximate, checked September 2026.What the other tools cost
Claude API vs the alternatives
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