Claude Haiku 4.5: Fast, Cheap, and Capable

Claude Haiku 4.5 is Anthropic's fastest and cheapest model, priced at $1 per million input tokens and $5 per million output, with a 200,000-token context window. It matches Claude Sonnet 4 on coding, scores 73.3% on SWE-bench Verified, and is the first Haiku with extended thinking and computer use built in.

We route a lot of high-volume, low-glamour work through Haiku 4.5 on this site — classification, extraction, first-draft summaries, and the parallel subagents that fan out under a bigger model. It changed the arithmetic of what belongs where. Below is the honest breakdown: what the model is, what it costs, how it stacks up against Claude Sonnet 5 and Claude Opus 4.8, when to reach for it, and where it genuinely falls short.

What is Claude Haiku 4.5?

Claude Haiku 4.5 is the small, speed-optimized tier of Anthropic's model family — the one built for volume rather than the hardest reasoning. What makes this release notable is that "small" no longer means "limited." According to Anthropic's launch announcement, Haiku 4.5 delivers near-frontier intelligence: it matches the previous flagship, Claude Sonnet 4, on agentic coding while running more than twice as fast and costing a third as much.

It handles both text and images, carries a 200,000-token context window, and is the first Haiku to ship with extended thinking, computer use, and context awareness. That last point matters more than the spec sheet suggests. Earlier Haiku models were fast text machines; this one can pause to reason, drive a browser, and call tools like bash, code execution, text editing, and web search. If you have only ever thought of Haiku as autocomplete-grade, this generation resets that assumption. For the full lineup and where each tier sits, our pillar guide Claude models explained lays out the whole family.

Claude Haiku 4.5 pricing and specs

The headline number is the price. At $1 per million input tokens and $5 per million output, Haiku 4.5 is the cheapest model Anthropic sells, and the gap to the mid-tier is large enough to change how you architect an application. The model overview in the Claude Platform docs lists the full specification, but here is what you actually need at a glance.

Two discounts stack on top and they are the real cost story for production workloads. Prompt caching cuts as much as 90% off repeated context — invaluable when every request shares the same system prompt or document. Batch processing takes another 50% off for non-urgent jobs. Run a nightly classification pass through the Batch API against cached context and the effective rate drops far below the sticker price. We cover how those levers compound in our Claude API pricing breakdown.

Haiku 4.5 vs Sonnet 5 vs Opus 4.8

The only way to judge Claude Haiku 4.5 is against its siblings, because the whole point is choosing the cheapest model that clears your quality bar. Here is how the current tiers compare on the numbers that drive the decision.

The pattern is clean: Haiku 4.5 is roughly a third the price of Claude Sonnet 5 and a fifth the price of Claude Opus 4.8, while running noticeably faster than both. What you give up is ceiling. Opus 4.8 leads on the toughest agentic benchmarks — it posts 69.2% on SWE-bench Pro, work that involves multi-hour tasks and sprawling codebases where Haiku will lose the thread. Sonnet 5 sits in the middle as the balanced default. Haiku 4.5 wins decisively on any task where speed and cost dominate and the reasoning demand is moderate.

A concrete rule we follow: if a task is well-defined and repeats thousands of times, start on Haiku 4.5 and only escalate the cases it fails. If a task is open-ended and you cannot describe the finish line in a sentence, start on Sonnet or Opus. Our Claude Haiku vs Sonnet comparison drills into that trade-off task by task, and Claude Sonnet 5 covers the mid-tier in depth.

When to pick Claude Haiku 4.5

The model earns its place in four situations, and recognizing them is most of the skill.

• High-volume, repetitive tasks. Tagging support tickets, extracting fields from documents, moderating comments, generating short product blurbs. When you are running a task tens of thousands of times, the price difference is the entire budget.
• Subagent orchestration. This is the pattern Anthropic highlights: a Sonnet or Opus planner breaks a job into parallel subtasks and hands each to a Haiku 4.5 worker. You get breadth cheaply while the expensive model does the thinking. If you build with Claude Code subagents, Haiku is the natural worker tier.
• Latency-sensitive experiences. Chat that has to feel instant, autocomplete, real-time suggestions. Haiku 4.5 is the fastest model Anthropic offers, so it fits interactive loops the larger tiers make sluggish.
• Cost-capped coding. At 73.3% on SWE-bench Verified, Haiku handles a large share of everyday code generation, debugging, and refactoring at a fraction of flagship pricing.

The inverse is just as useful. Reach past Haiku 4.5 when a task needs sustained multi-step reasoning, deep architectural judgment, or reliability on long-horizon agentic work where a single wrong turn compounds. That is Opus territory. The Claude Opus 4.8 writeup covers where the ceiling actually matters.

The real limits of Haiku 4.5

Being honest about a model's edges is how you avoid deploying it into a task that quietly degrades. Claude Haiku 4.5 is remarkable for its class, but it is still the small tier, and three limits are worth naming.

First, the reasoning ceiling is lower than Sonnet or Opus. On genuinely hard, multi-hour agentic problems — the kind Opus 4.8's SWE-bench Pro score is built to measure — Haiku loses coherence over long chains where the flagship holds it. It gets you 90% of Sonnet 4.5's agentic-coding quality in Anthropic's cited evaluations, and that last 10% is exactly the hard part.

Second, the context window is 200,000 tokens, not the million-token window the larger Sonnet tier can reach. For most jobs 200K is plenty, but if you are stuffing an entire monorepo or a book-length corpus into one prompt, that is a real constraint. Claude context window explains how to work within it.

Third, extended thinking is powerful but not free — thinking tokens bill as output at $5 per million, so a heavy-reasoning Haiku call can cost more than a plain Sonnet call. If you turn the reasoning budget up on every request, you erode the cost advantage that made you pick Haiku. Use extended thinking deliberately, not by default.

How to access Claude Haiku 4.5

You can reach the model through every surface Anthropic ships. In the Claude apps it powers free-tier responses; developers call it through the Claude API with the identifier claude-haiku-4-5; and it is available on the major clouds — Amazon Bedrock, Google Vertex AI, and Microsoft Foundry — for teams that need it inside existing infrastructure. It also drives the fast agents in Claude Code when you route work to the cheaper tier. Whichever door you use, the model, the 200K context, and the tool support are the same; only billing and access controls differ. For a first API call, our Claude API getting started guide has the minimal setup.

That reach, plus the price, is why we treat Haiku 4.5 as the default first stop for any new automation and only escalate the tasks that prove they need more. Start cheap, measure, promote the failures. It is the cleanest cost discipline the current lineup allows.

Claude pricing at a glance

For the full breakdown of every plan, see our how much Claude costs guide.