What Claude Haiku 4.5 Is
Claude Haiku 4.5 is Anthropic's fastest and cheapest model — $1 input / $5 output per 1M tokens — built for high-volume, latency-sensitive work where you want Claude's reliability without flagship pricing. It's the bottom rung of the Claude ladder: Haiku for speed and volume, Sonnet 4.6 for scaled production, Opus 4.8 for the hardest tasks.
Pricing in Context
| Model | Input | Output |
|---|---|---|
| Claude Haiku 4.5 | $1 | $5 |
| Claude Sonnet 4.6 | $3 | $15 |
| Claude Opus 4.8 | $5 | $25 |
Batch API halves it (50% off); prompt caching cuts cached input ~90%. On LinkModel it runs behind one key with the rest of the Claude family, up to 30% below official.
When Haiku Is Enough
- High-volume classification, extraction, tagging, routing — where a smaller model clears the bar and volume drives the bill.
- Latency-sensitive UX — chat suggestions, autocomplete, live features that need fast responses.
- Agent sub-steps — the cheap default in a routed stack, escalating only hard steps to Sonnet/Opus.
- First-pass drafts — draft on Haiku, refine on Sonnet.
When to Escalate
- Nuanced reasoning or judgment → Sonnet 4.6.
- Correctness-critical or hardest agentic coding → Opus 4.8.
The tiered pattern — Haiku default, escalate on difficulty — is the single biggest cost lever in a Claude deployment. Details in how to reduce AI API costs.
Haiku vs Cheaper Rivals
At $1/$5, Haiku isn't the cheapest model overall — DeepSeek V4 Flash ($0.14/$0.28) and Gemini Flash-Lite ($0.10/$0.40) undercut it — but it buys Anthropic's safety profile and instruction-following at a fraction of Opus. If you specifically want Claude quality cheaply, Haiku is the pick; if you want the absolute lowest cost, see cheapest LLM API.
How to Call It
curl -X POST https://api.linkmodel.ai/v1/chat/completions \
-H "Authorization: Bearer $LINKMODEL_API_KEY" -H "Content-Type: application/json" \
-d '{ "model": "claude-haiku-4-5-20251001", "messages": [{"role":"user","content":"Classify these tickets by urgency: ..."}] }'Confirm the exact chat endpoint and schema in the docs. Cache a stable prompt prefix to capture the ~90% discount.
Bottom Line
Claude Haiku 4.5 is the fast, cheap Claude for high-volume and latency-sensitive work — default to it, escalate to Sonnet/Opus only when the task demands it. Compare the full ladder in the Claude Opus pricing guide and best LLM API.
Start free with a $1 credit and test Haiku on your high-volume tasks.
