Claude Haiku 4.5 is Anthropic's fastest and most affordable model: instant responses for high-volume tasks, drafts and quick lookups.
What Claude Haiku 4.5 is best for
Quick lookups, definitions and short answers
First drafts of emails, captions and social posts
Bulk processing: classify, summarise or tag at scale
Rapid iteration on ideas before switching to a larger model
Cost-efficient coding snippets and simple bug fixes
How to use Claude Haiku 4.5
Step 1
Keep prompts short and specific so Claude Haiku 4.5 can return a fast answer: it shines on quick lookups, definitions and first drafts rather than slow, heavy reasoning.
Step 2
Batch repetitive work by feeding Haiku 4.5 items one after another to classify, tag, summarize or rewrite at high volume while keeping credit use low.
Step 3
Use it to iterate quickly on rough ideas or drafts, then escalate to Sonnet or Opus only for the parts that need deeper reasoning.
Example prompts
Frequently asked questions
When should I use Haiku instead of Sonnet?
Use Haiku when you need a fast, cheap answer and the task is straightforward. Switch to Sonnet or Opus for anything requiring sustained reasoning.
How fast is Claude Haiku 4.5?
Haiku is Anthropic's lowest-latency model, typically responding in under 2 seconds for short prompts.
Is Haiku as accurate as Sonnet?
On simple tasks the quality is very close. On complex reasoning or long-form writing, Sonnet and Opus pull ahead.
Can I use Haiku for free?
Yes. Haiku consumes fewer credits than Sonnet or Opus, making it the best choice for maximising your free monthly allowance.
