Last updated: October 29, 2026
Pick Claude Haiku if you’re running lots of simple, repeatable tasks like sorting, tagging, extracting data or routing requests. Pick Claude Sonnet when the task needs real reasoning: writing, multi-step analysis or coding. The price gap is now huge. As of October 2026, Haiku 5.5 costs $0.10 per million input tokens on prompts under 100,000 tokens, against $2 for Sonnet 5.5. That makes Sonnet 20 times more expensive on short prompts.
(Looking for poetry? A haiku is a three-line poem, a sonnet has fourteen lines. This page is about Anthropic’s Claude AI models.)
Haiku vs Sonnet at a glance
| Claude Haiku 5.5 | Claude Sonnet 5.5 | |
|---|---|---|
| Anthropic’s description | For high-volume, latency-sensitive tasks such as classification, extraction and routing | The best combination of speed and intelligence |
| Speed | Fastest | Fast |
| Input price (per million tokens) | $0.10 for prompts up to 100K tokens, $0.50 above | $2 |
| Output price (per million tokens) | $0.50 for prompts up to 100K tokens, $2.50 above | $10 |
| Context window | 1M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Thinking | Adaptive, medium effort by default | Adaptive, high effort by default |
| API model ID | claude-haiku-5-5 | claude-sonnet-5-5 |
Source: Anthropic’s models overview and pricing page, checked October 29, 2026. Both models take text and images as input and support tool use.
What the price gap means in practice
Per-token prices are hard to picture, so here are two worked examples using the list prices above.
A busy support bot. Say you handle one million requests a month, each with about 2,000 tokens of input and 500 tokens of output. On Haiku 5.5 that’s roughly $200 for input plus $250 for output, about $450 a month. On Sonnet 5.5 it’s $4,000 plus $5,000, about $9,000 a month. Same traffic, 20 times the bill.
One long document. Now take a single request with a 150,000-token prompt, like a long contract, and a 2,000-token answer. Because that prompt is over Haiku’s 100K threshold, Haiku charges its higher rate: about 8 cents for the request. Sonnet charges about 32 cents. The gap shrinks to 4 times.
So Haiku’s advantage is biggest on short, high-volume work, which is what Anthropic built it for. On long prompts it’s still cheaper, just by less.
When to choose Haiku
- Classifying or tagging large batches of text, like support tickets or reviews
- Pulling structured data out of documents, emails or forms
- Routing requests, deciding which tool, team or model should handle something
- Anything users wait on in real time, where speed matters more than depth
- First-pass filtering before a bigger model handles the hard cases
A common setup uses both: Haiku handles the easy majority and passes the tricky requests to Sonnet. That keeps most of your traffic on the cheap model without making the hard answers worse.
When to choose Sonnet
- Writing that people will actually read, like articles, emails or reports
- Coding beyond quick snippets
- Multi-step analysis where the answer depends on reasoning, not lookup
- Agent-style tasks that run several tools in a row
- Any task where a wrong answer costs more than the price difference
Sonnet also runs at a higher default thinking effort, so it spends more effort working through a problem before answering. That’s part of why it’s slower and better on hard tasks.
What about Opus and Fable?
Haiku and Sonnet aren’t the top of the range. Anthropic’s current lineup also includes Claude Opus 5.5 ($4 input, $20 output per million tokens), which Anthropic suggests as the starting point for most workloads, and Claude Fable 5.1 ($10 and $50) for the hardest reasoning and long-running agent work. If Sonnet keeps falling short on a task, test Opus before assuming the task can’t be done.
How the 5.5 models compare with the older 4.5 ones
If you’re still on Claude 4.5 models, the newer ones are cheaper on paper. Anthropic’s pricing page lists Haiku 4.5 at $1 input and $5 output per million tokens, and Sonnet 4.5 at $3 and $15. Haiku 5.5 on short prompts is a tenth of Haiku 4.5’s price, and Sonnet 5.5 costs about two thirds of Sonnet 4.5. Test your own prompts before switching, since behaviour changes between model generations.
FAQs
Is Claude Haiku or Sonnet better?
Sonnet is more capable, Haiku is faster and much cheaper. Use Haiku for simple, high-volume tasks and Sonnet for writing, coding and reasoning.
How much cheaper is Haiku than Sonnet?
As of October 2026, Claude Haiku 5.5 is 20 times cheaper than Sonnet 5.5 on prompts under 100,000 tokens, and about 4 times cheaper on longer prompts.
Do Haiku and Sonnet have the same context window?
Yes. Both Claude Haiku 5.5 and Sonnet 5.5 support a 1M-token context window and up to 128K output tokens.
Can I use Haiku and Sonnet together?
Yes. A common pattern is letting Haiku handle routine requests and routing the harder ones to Sonnet, which keeps costs down without hurting quality on difficult tasks.
For how Claude compares with OpenAI’s models, see our ChatGPT vs Claude comparison.
