Claude Opus vs Sonnet vs Haiku: Which Model for Which Coding Task (2026)
By Eric Bush · July 15, 2026 · 7 min read
Three Models, One 5x Price Spread
Anthropic's Claude family gives you three coding-capable tiers, and the price gap between them is large enough that picking the wrong one is a real waste of money:
| Model | Input / Output (per M) | Character |
|---|---|---|
| Claude Opus 4.8 | $5 / $25 | Deepest reasoning, highest cost |
| Claude Sonnet 4.6 | $3 / $15 | Balanced everyday workhorse |
| Claude Haiku 4.5 | $1 / $5 | Fast and cheap for simple work |
Opus output costs 5x what Haiku output costs. Run everything on Opus and you overpay massively on tasks Haiku would nail; run everything on Haiku and you will waste even more redoing work it got wrong. The skill is matching the model to the task.
When to Use Haiku 4.5
Haiku is your default for anything that is well-defined and mechanical. It handles the bulk of day-to-day coding volume at a fraction of the cost:
- Autocomplete and inline suggestions
- Simple, localized edits — renames, small refactors, adding a parameter
- Boilerplate: getters/setters, config files, standard CRUD handlers
- Formatting, syntax fixes, and mechanical translations between similar languages
- First-pass drafts you will review and refine anyway
If the task has one obvious correct answer and little ambiguity, Haiku is almost always the right call. Paying Opus rates for boilerplate is pure waste.
When to Use Sonnet 4.6
Sonnet is the workhorse — the model most developers should run most of the time. It handles real feature work where there is some judgment involved but not deep architectural uncertainty:
- Implementing a feature from a clear spec
- Multi-file changes with moderate complexity
- Writing tests, debugging typical bugs, code review
- Refactoring that touches several related pieces
- Explaining unfamiliar code and answering design questions
At $3/$15 it is 40% cheaper than Opus on both input and output, and for the majority of coding tasks the quality difference is invisible. If you are unsure which tier to reach for, Sonnet is the safe default.
When to Use Opus 4.8
Opus earns its premium on the hard problems — the ones where a better answer is worth paying for because a wrong answer is expensive to recover from:
- System architecture and high-stakes design decisions
- Debugging subtle, deep bugs that resist ordinary approaches
- Large, tangled refactors across many interdependent files
- Complex algorithmic work and tricky concurrency or performance problems
- Anything where a mistake cascades into hours of rework
The logic is straightforward: on a genuinely hard task, Opus getting it right the first time is cheaper than Sonnet or Haiku failing twice and forcing you to redo the work. The premium buys reliability where reliability matters.
The Practical Strategy: Escalate, Don't Default
The cost-optimal habit is to start low and escalate only when needed. Reach for Sonnet by default, drop to Haiku for clearly simple tasks, and escalate to Opus only when a task is genuinely hard or when a cheaper model has already stumbled. Many teams formalize this as tiered routing: cheap models handle the volume, the frontier model is reserved for the few percent of tasks that need it.
Avoid the two common mistakes: running everything on Opus "to be safe" (you overpay 5x on easy work), and running everything on Haiku "to save money" (you pay in rework and frustration). The savings live in the routing, not in any single model.
Want to see what a tiered mix does to your monthly bill? Model different splits of Opus, Sonnet, and Haiku usage in the AI Cost Estimator to find the blend that fits your workload.
Want to calculate exact costs for your project?
Frequently Asked Questions
What is the price difference between Claude Opus, Sonnet, and Haiku?
As of mid-2026: Claude Opus 4.8 is $5 input / $25 output per million tokens, Sonnet 4.6 is $3/$15, and Haiku 4.5 is $1/$5. Opus output costs 5x what Haiku output costs, so matching the model to the task has a large effect on your bill.
Which Claude model should I use for everyday coding?
Sonnet 4.6 is the workhorse most developers should use most of the time. At $3/$15 it's 40% cheaper than Opus and handles feature work from specs, multi-file changes, tests, debugging, and code review with quality that's usually indistinguishable from Opus. It's the safe default when unsure.
When is Claude Opus worth the extra cost?
On genuinely hard tasks — system architecture, subtle deep bugs, large tangled refactors, complex algorithms — where a wrong answer is expensive to recover from. Opus getting it right the first time is cheaper than a weaker model failing twice and forcing rework. The premium buys reliability where it matters.
What's the cheapest way to use the Claude model family?
Escalate, don't default: use Sonnet by default, drop to Haiku for clearly simple tasks (boilerplate, autocomplete, renames), and escalate to Opus only when a task is genuinely hard or a cheaper model has already stumbled. The savings come from routing, not from any single model.
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