What Claude Sonnet 5.5 is
Claude Sonnet 5.5 is an Anthropic model that went live on OpenRouter on September 28, 2026. It follows Claude Sonnet 5. Per standard answer it costs about the same, $0.0070 against $0.0070, and it keeps the same 1M token context window.
| Released | September 28, 2026 |
| Provider | Anthropic |
| Context window | 1M tokens |
| Input, per million tokens | $2 |
| Output, per million tokens | $10 |
| Credits per message in Whizi | 10 |
| Minimum Whizi plan | Pro |
How to try Claude Sonnet 5.5 in Whizi
Whizi puts Claude Sonnet 5.5 in the same model picker as ChatGPT, Claude and Gemini, so there is no separate Anthropic account or API key to set up. Pick a plan on the pricing page, open a new chat, choose Claude Sonnet 5.5 in the model picker and send your first message.
Each message costs 10 credits, whatever its length. If a question turns out to suit another model better, switch in the same conversation and the thread carries across. See switching models mid-conversation.
What Claude Sonnet 5.5 costs
List rates are what the provider charges per token. The cost of one standard answer is the more useful number, because it prices the same unit of work across every model regardless of how each one is billed.
| Input, per million tokens | $2 |
| Output, per million tokens | $10 |
| One standard answer | $0.0070 |
| One thousand answers | $7.00 |
| Context window | 1M tokens |
| Credits per message in Whizi | 10 |
| Minimum Whizi plan | Pro |
| Rank by cost, of 114 priced models | 95 |
Prices are the published Anthropic rates as carried by OpenRouter, last refreshed 2026-09-29. The full dataset covering all 125 models from 33 providers is the AI model cost index, which is free to reuse with attribution.
What it costs inside Whizi
Whizi meters messages in credits rather than tokens, and Claude Sonnet 5.5 is charged at 10 credits per message. The cost does not change with the length of your message or the length of the answer, so a one line question and a long document analysis cost the same.
| Plan | Price per month | Monthly credits | Messages on this model |
|---|---|---|---|
| Pro | $29.99, or $19.99 billed yearly | 2,000 | 200 |
| Powerhouse | $49.99, or $34.99 billed yearly | 8,000 | 800 |
Claude Sonnet 5.5 is included from the Pro plan up. Pro is a curated tier rather than everything cheap: one or two current flagships per model family, each fast tier, and the high volume workhorses. See plans and limits.
- Input $2 and output $10 per million tokens
- $0.0070 for one standard answer, $7.00 for a thousand
- 1M token context window
- 10 credits per message inside Whizi
- Requires the Pro plan or above
- Ranks 95 of 114 priced models by cost per answer
Frequently asked questions
What is Claude Sonnet 5.5?
Claude Sonnet 5.5 is an Anthropic model released on September 28, 2026, with a 1M token context window. It follows Claude Sonnet 5. Per standard answer it costs about the same, $0.0070 against $0.0070, and it keeps the same 1M token context window.
How do I use Claude Sonnet 5.5?
Sign up for Whizi, open a new chat and choose Claude Sonnet 5.5 in the model picker. It is available on the Pro plan and above at 10 credits per message, with no Anthropic account or API key needed.
How much does Claude Sonnet 5.5 cost?
$2 per million input tokens and $10 per million output tokens at list rates, which works out to $0.0070 for one standard answer of 1,000 tokens in and 500 out, or $7.00 for a thousand of them. Inside Whizi it is 10 credits per message on a monthly allowance, rather than metered per token.
Which Whizi plan includes Claude Sonnet 5.5?
Pro and above, which is $29.99 per month or $19.99 billed yearly. At 10 credits per message, a Pro allowance of 2,000 credits covers 200 messages on this model if you spend the whole allowance here, and most people mix in a 1 credit model for routine work so it goes further.