Claude Opus 4.8 vs Sonnet 4.6 vs Haiku 4.5: Which to Use

The three models form a deliberate ladder. **Haiku 4.5** is the fast, low-cost tier built for speed and scale — it shines on simple, well-defined tasks you run thousands of times. **Sonnet 4.6** is the balanced workhorse: strong general capability and good speed, the right default for most real workloads. **Opus 4.8** is the most capable tier, designed for the hardest problems where a single wrong step compounds.

Crucially, the cost levers are identical across all three. Each supports prompt caching and batch processing, and the Claude API exposes the same tools regardless of tier — so the only variable in your decision is whether a given task needs more capability than the cheaper tier provides. Check the current per-token rates and discounts on the Anthropic pricing page and the models overview.

Reach for Haiku 4.5 when speed and unit cost matter more than the last few points of capability. It is well suited to classification, routing, extraction, short summaries, autocomplete-style suggestions, lightweight chat, and any task you run at high volume where each call is simple and well-scoped.

Haiku is also the natural first stage in a pipeline: use it to triage, filter, or pre-process, then escalate only the requests that need a bigger model. For repetitive, structured jobs, pair Haiku with structured output schema design patterns to keep responses machine-readable and cheap to parse.

Sonnet 4.6 is the right default for the majority of production and everyday work. It balances capability and speed well enough that most teams won't notice a meaningful gap to Opus on routine drafting, summarization, customer-facing chat, and the bulk of code generation — while costing less and responding faster.

If you are unsure which tier to start with, start here. Sonnet is strong enough to be your baseline and cheap enough to run at scale. For content workflows it pairs well with our business email generator and blog post outline prompts. For a head-to-head against the top tier, see our dedicated Opus 4.8 vs Sonnet 4.6 comparison.

Opus 4.8 is Anthropic's most capable model, and that capability shows up most on tasks where errors are expensive: complex multi-file refactors, dense technical reasoning, long agentic chains that require planning and self-correction, and ambiguous problems where smaller models take the obvious-but-wrong path.

A useful heuristic: if you find yourself re-prompting Sonnet or Haiku two or three times to fix the same class of mistake, the retries often cost more in time and tokens than running Opus once. Opus is also the safer default for high-stakes, one-shot outputs — a migration plan, a security-sensitive code change, a careful analysis — where you would rather pay more than risk a subtle error.

Opus and Sonnet both support an extended thinking mode for harder reasoning; see the models overview for which tiers expose it and how to enable it.

Pick **Haiku 4.5** if you need the cheapest, fastest option for simple high-volume tasks and you can accept a lower capability ceiling. Pick **Sonnet 4.6** if you want one default that handles most work well — it is the safest starting point for the majority of teams. Pick **Opus 4.8** if the task genuinely needs the deepest reasoning, complex or long agentic coding, or it is a costly one-shot output.

The most cost-effective pattern is to not pick just one. Default to Sonnet, send simple bulk work down to Haiku, and escalate only the hardest or highest-stakes requests up to Opus. Because prompt caching and batch processing apply to every tier, those savings compound whichever model handles the request — review the live pricing page and prompt caching docs for the current math.