Model · Anthropic

Claude Haiku 4.5

Cheap, fast Claude for extraction and classification.

Provider
Anthropic
Family
Claude 4.x
Context window
200K tokens
Modality
text, tool use
Knowledge cutoff
January 2026
Last updated
2026-04-19

At a glance

Claude Haiku 4.5 is Anthropic's speed tier — low latency, low cost, and ideal for extraction, classification, and routing tasks that do not need Sonnet or Opus.

Strengths

  • Lowest cost in the Claude 4.x line
  • Fast enough for real-time routing and classification
  • Good at short structured extraction

Weaknesses

  • Not a reasoning model — escalate anything complex
  • Weaker long-context performance than Sonnet or Opus

Best for

  • High-volume extraction and classification
  • Router 'first-pass' model in a multi-tier stack
  • Simple transformations over short text

Where Haiku actually wins

Haiku 4.5's strength is throughput — you can send it 10x the traffic of Opus for the same budget. That makes it the right model for classification (is this support ticket billing or tech?), extraction (pull these 5 fields out of an invoice), and first-pass routing (can a small model answer this, or do we need Sonnet?).

Haiku in a routed stack

A good router sends 30–60% of traffic to Haiku. The router decides whether Haiku's answer is confident enough; if not, it retries on Sonnet or escalates to Opus. That pattern is the single biggest cost lever in an AI product.

Frequently asked questions

What is Claude Haiku 4.5 best for?

Haiku 4.5 is best for short, high-volume tasks: classification, extraction, routing, and first-pass agent steps. Use it for anything that does not require deep reasoning.

Is Haiku 4.5 good enough for chat?

For simple, narrow chat surfaces — yes. For chat that needs to reason across documents or plan multi-step actions, use Sonnet 4.6 instead.