Claude Haiku is 📝Anthropic's fastest and lowest-cost model tier in the 📝Claude family; the current model, Claude Haiku 4.5, was released October 15, 2025 and is priced at $1 / $5 per million tokens.

Claude Haiku is the entry tier beneath 📝Claude Sonnet and 📝Claude Opus, built for high-volume, latency-sensitive work such as classification, extraction, real-time chat, and sub-agent tasks inside larger agent systems. Anthropic describes Haiku 4.5 as its fastest model with near-frontier intelligence. As of September 2026 it is also the oldest model in Anthropic's current lineup: it predates the adaptive-thinking and 1M-token-context generation, and Anthropic has not announced a Claude 5-generation Haiku.

Key Facts

Current model: Claude Haiku 4.5 (claude-haiku-4-5-20251001, alias claude-haiku-4-5), released October 15, 2025
Pricing: $1 input / $5 output per million tokens; cached reads $0.10
Context window: 200K tokens, 64K max output
Thinking: manual extended thinking with budget_tokens; no effort parameter
Knowledge cutoff: February 2025
Retirement: not sooner than October 15, 2026
Status as of: September 28, 2026

Model Lineage

Claude 3 Haiku (March 13, 2024) — the smallest and fastest Claude 3 model; retired April 20, 2026
Claude 3.5 Haiku (October 22, 2024) — faster, stronger successor to Claude 3 Haiku; retired February 19, 2026
Claude Haiku 4.5 (October 15, 2025) — current; Anthropic's recommended replacement for both earlier Haiku models

Claude Haiku 4.5 (Current)

Claude Haiku 4.5 is the only current Claude model that still uses manual extended thinking rather than adaptive thinking, and the only one limited to a 200K-token context window; every other model in the lineup offers 1M tokens. It is available on the Claude API, Amazon Bedrock, 📝Google Cloud, Microsoft Foundry, and Claude Platform on AWS. Its retirement commitment runs only to October 15, 2026, so teams building on it should watch Anthropic's deprecations page for a successor or migration notice.

Why It Matters

Haiku sets the cost floor for running Claude at scale. Because multi-agent systems often route simple, repetitive steps to the cheapest capable model, Haiku's price and speed shape the economics of agent fleets more than its benchmark scores do. The widening gap between Haiku 4.5 and the Claude 5.5 generation also makes Claude Sonnet 5.5, at twice Haiku's price, a common substitute for workloads that need longer context or newer knowledge.

FAQ

What is the latest Claude Haiku model?

Claude Haiku 4.5, released October 15, 2025, is the latest Haiku model. Anthropic has not announced a newer Haiku as of September 28, 2026.

How much does Claude Haiku cost?

Claude Haiku 4.5 costs $1 per million input tokens and $5 per million output tokens, making it the cheapest model in Anthropic's current lineup.

What is Claude Haiku's context window?

Claude Haiku 4.5 has a 200,000-token context window and a 64,000-token maximum output, compared with 1M tokens and 128K output on Sonnet 5.5, Opus 5.5, and Fable 5.1.

When will Claude Haiku 4.5 be retired?

Anthropic commits to keeping Claude Haiku 4.5 available until at least October 15, 2026, and gives at least 60 days' notice before retiring a publicly released model.

📝Claude Model Glossary — every Claude model by tier and release date
📝Claude Opus 5.5 — the current Opus model
📝Claude Mythos — the tier at the top of the lineup