Opus, Sonnet and Haiku are the same family at three points on the capability-versus-cost curve. The cheapest correct answer is almost never the biggest model — here is how to choose per task.
| Use case | Recommended tier | Why |
|---|---|---|
| Customer support chat | Haiku | High volume, short answers, latency matters more than depth. |
| Code generation & refactoring | Sonnet | Best balance of coding quality and cost for everyday work. |
| Complex multi-step agents | Opus | Long-horizon planning and tool use where a wrong step is expensive. |
| Architecture & code review | Opus | Deep reasoning over large context beats raw throughput. |
| Bulk classification & tagging | Haiku | Simple, repetitive judgements at the lowest cost per call. |
| Long document analysis | Sonnet | Large context at mid-tier pricing; escalate to Opus only if quality slips. |
| Content drafting | Sonnet | Output-heavy work where output token price dominates the bill. |
| Data extraction to JSON | Haiku | Schema-constrained output needs speed, not deep reasoning. |
| Model | Tier | Context | Our price in / out | Discount |
|---|---|---|---|---|
| Claude Opus 4.8 | Flagship | 200K tokens | $3 / $15 | 80% |
| Claude Fable 5 | Newest | 200K · 1M variant | $3 / $15 | 80% |
| GPT-5.5 | Flagship | 256K tokens | $3 / $12 | 70% |
| Claude 1M Context | Long context | 1,000,000 tokens | $1.8 / $6.75 | 70% |
| GPT-5 | Popular | 256K tokens | $1.5 / $6 | 70% |
| Claude Sonnet 4.6 | Best value | 200K · 1M beta | $0.9 / $4.5 | 70% |
| Gemini 3 Pro | Multimodal | 1M tokens | $1 / $6 | 60% |
| MiniMax M3 | New | 1M tokens | $0.5 / $2.5 | 58% |
| Claude Haiku 4.5 | Fastest | 200K tokens | $0.4 / $2 | 60% |
| Gemini 3 Flash | Fast | 1M tokens | $0.2 / $1.2 | 60% |
Prices are per million tokens. Run your own numbers in the cost calculator.
They are three sizes of the same model family. Opus is the most capable and most expensive, tuned for deep reasoning and agentic work. Sonnet sits in the middle and is the usual production default, especially for coding. Haiku is the fastest and cheapest, built for high-volume, low-complexity calls.
Sonnet is the right default for day-to-day code generation, refactoring and test writing — it is markedly cheaper than Opus while staying strong at code. Move to Opus for architecture decisions, hard debugging and long autonomous agent runs where a wrong step costs more than the token difference.
Yes. Every model is available through the same base URL and API key, so switching is a one-line change to the model ID in your request. That also makes tier-escalation easy to implement: try the cheap model first, retry with a bigger one only on failure.
The window itself is free; you pay for the tokens you actually send. A large window matters because it lets you send more context when you need to — but filling it on every call is one of the most common sources of an unexpectedly large bill.
Same models, same context windows, one drop-in base URL. Pay as you go or take a flat-rate unlimited plan.
Get an API key See unlimited plansClaudeAPIKey.dev is an independent API gateway and is not affiliated with, endorsed by, or sponsored by Anthropic. “Claude” and “Anthropic” are trademarks of Anthropic. Official Anthropic list prices shown for comparison are taken from Anthropic’s published pricing and may change; our rates are read from our own live catalogue. Estimates are calculated from the token counts you enter and will differ from real usage.