Anthropic API review

Anthropic's API is the strongest choice for long-context and agentic work where per-token price is not the only factor. Claude Haiku 5.5 costs $0.10 per 1M input tokens and $0.50 per 1M output tokens for prompts up to 100,000 tokens, Claude Sonnet 5.5 costs $2 and $10, and Claude Opus 5.5 $4 and $20. The models overview lists a 1M-token context window and 128K max output on current models, and Claude 4.6 and later models other than Haiku 5.5 bill the full 1M window at standard rates. Prompt caching charges cache hits at 5% of the input price, the Batch API halves prices, and the two discounts stack. Code execution is free when paired with web search or web fetch. Rate limits are set by usage tier, with monthly spend caps of $500 on Start, $1,000 on Build and $200,000 on Scale, which new apps can outgrow quickly. Haiku 5.5 input also rises from $0.10 to $0.50 per 1M tokens above 100,000-token prompts.

Who it is for

Teams building coding tools, agents and long-document apps that want a 1M-token context at standard pricing.

Price

Pay as you go; Claude Haiku 5.5 costs $0.10 per 1M input tokens for prompts up to 100,000 tokens.

Claude Haiku 5.5 For high-volume, latency-sensitive tasks such as classification, extraction, and routing $0.10 / MTok for prompts up to 100,000 tokens
Quoted from the vendor pricing page on November 7, 2026.

Key features

• Claude Fable, Opus, Sonnet and Haiku models with 1M-token context
• Prompt caching with cache hits at 5% of the input price
• Batch API at 50% off input and output tokens
• Code execution free when used with web search or web fetch
• US-only inference option through the inference_geo parameter

Strengths and weaknesses

• Strength: Full 1M context at standard pricing on Claude 4.6 and later, except Haiku 5.5
• Strength: Discounts for batch and caching stack
• Strength: Same models on three major clouds
• Weakness: Haiku 5.5 input costs five times more for prompts over 100,000 tokens
• Weakness: Monthly spend caps per tier, starting at $500 on the Start tier
• Weakness: Only a small amount of free credits for new users

Key facts

• Claude Haiku 5.5: $0.10 in, $0.50 out per 1M tokens up to 100K prompts
• Claude Sonnet 5.5: $2 in, $10 out per 1M tokens
• Context window: 1M tokens, 128K max output
• Spend caps: Start $500, Build $1,000, Scale $200,000 a month

Where it ranks

Anthropic API is No. 3 in our Best LLM APIs verdict.