Claude Sonnet 5.5
Anthropic's balanced Claude for programming and day-to-day work, with a reasoning effort you can raise, available anonymized through NeverNo.
Updated November 8, 2026
Readable on your devices only.
Your conversation is readable on your device, and on your other devices if you sync them. Nowhere else.
Unreadable to us.
Your message passes through without being written down; your chats are only ever stored encrypted.
The model doesn’t know you.
It gets the question, never your email, your account or your IP address.
Nothing is left along the way.
The reply comes back and is stored here, encrypted; even when you sync, your key never reaches us in the clear.
At a glance
| Maker | Anthropic |
|---|---|
| Context | 200,000 tokens |
| Longest reply | 16,384 tokens |
| Strengths in the app | Hard questions, Code, Reads images |
| Reasoning | Always on |
| Who can use it | Paid plans |
| How it’s paid | Credits, from the first use |
| Privacy | Anonymized: NeverNo sends the request to its maker without your name, account or IP address. The maker still reads the text, applies its own rules and may keep it for a while under its own policy.Some requests its maker doesn’t allow are answered by one of NeverNo’s private models instead, and the app tells you so. |
Price
What the app charges, read from the same table the servers bill with. 1 credit = $0.01.
| Typical message (2,000 tokens read, 600 written) | 2.64 credits ($0.0264) |
|---|---|
| Million tokens read | 527.5 credits ($5.28) |
| Million tokens written | 2,637.5 credits ($26.38) |
Measured
Our own measurements and one third-party score, each with its conditions and date. Figures are not rounded.
| Median time to the first word | 3.38 sOur client, 12 everyday requests run 3 times each, November 9, 2026 |
|---|---|
| arena.ai Text Arena, overall score | 1,477Third-party leaderboard, page dated October 27, 2026 |
What it is
Claude Sonnet 5.5 is the middle of Anthropic's range and, for many people, the Claude they keep open all day. On NeverNo it is tagged for code and for general intelligence in the model selector: it writes and reviews programs, explains errors, drafts documents, answers technical questions and reads screenshots, at a credit cost below Claude Opus 5.5 and Claude Fable 5.2.
Unlike Opus and Fable, Sonnet lets you choose how hard it thinks. In the selector, the Reasoning setting offers Adaptive, which is the default and keeps answers quick, and High, which gives it more room to reason on a difficult bug or a tricky design question. It always reasons to some degree; High simply buys more thinking when you need it.
Access is anonymized: NeverNo passes your request to Anthropic without your name, account or IP address, and your history stays encrypted in your browser. Anthropic still reads the text it receives, applies its own rules and may keep it for a while under its own policy, so Sonnet may refuse some requests. Some requests its maker does not allow are answered by one of NeverNo's private models instead, and the app tells you so.
Sonnet 5.5 holds 200,000 tokens of context and writes up to 16,384 tokens per answer. On the arena.ai Text Arena (overall score, page dated October 27, 2026) it scores 1477. It is a premium model on paid plans, paid in credits per message.
Strengths
Tagged for code: generating functions, reviewing a pull request, writing tests, translating between languages and frameworks, explaining a stack trace.
Adjustable reasoning: Adaptive for speed on everyday prompts, High when a question needs real thought, chosen per conversation.
Fewer credits than Claude Opus 5.5 and Claude Fable 5.2, so it suits long working sessions where many messages add up.
Reads images: a screenshot of an error, a UI mock-up or a whiteboard diagram can be the starting point of a task.
Anonymized: no Anthropic account, nothing that identifies you sent with the text, conversations stored encrypted in your browser.
Limits
It costs credits on a paid plan; for simple lookups and short chats, an included model or Claude Haiku 5.5 is more economical.
Its arena.ai Text Arena score (1477) is below Claude Opus 5.5 (1509): for polished long-form writing or a sensitive analysis, Opus is the stronger pick.
Reasoning cannot be switched off entirely: the selector offers only Adaptive and High, so even trivial prompts carry a little thinking.
Anthropic reads the request and applies its own rules, so a refusal is possible; some out-of-policy requests are handed to a private NeverNo model, and the app shows it.
When to choose it
Pair programming
Paste a function, describe the bug or the feature, and iterate: Sonnet proposes code, explains the change, writes the tests and adjusts when you push back. With 200k tokens it can see several files and the error log together.
Everyday work assistant
Turning meeting notes into a summary with action items, rewriting a paragraph for a different audience, building a spreadsheet formula, preparing interview questions, comparing two supplier quotes: the routine tasks of a working day, handled quickly on Adaptive, so you spend your attention on decisions instead of formatting.
Understanding something from a screenshot
Send a capture of an error dialog, a configuration screen or a chart, and ask what it means and what to do next. Raise reasoning to High if the answer is not obvious, for instance when a misconfigured setting hides several layers deep.
Prompt tips
For code, give the language, the version and the constraint that matters (« no new dependency », « must stay compatible with the current API »); Sonnet respects clearly stated boundaries well.
Start on Adaptive and switch to High only when the first answer is shallow or wrong: you keep speed for easy turns and spend extra thinking where it pays.
Ask for a diff or only the changed lines on long files; answers are capped at 16,384 tokens, and a focused patch is easier to review anyway.
Frequently asked questions
Is Claude Sonnet 5.5 free on NeverNo?
No. Claude Sonnet 5.5 is a premium model on paid plans, paid in credits per message. The model selector shows an estimate for a typical exchange before you write.
Is Claude Sonnet 5.5 private on NeverNo?
It is anonymized: Anthropic gets your text without your name, account or IP address, and your conversation history is kept encrypted in your browser. Anthropic still reads the request, applies its rules and may retain it for a time. For full privacy, NeverNo's private open models never involve a closed company.
What is Claude Sonnet 5.5's context length?
200,000 tokens, with replies of up to 16,384 tokens. It also accepts images in your messages.
Claude Sonnet 5.5 or GPT-6.1 Sol: which is better for my work?
Both are anonymized premium models with 200k context and image reading. Sonnet 5.5 is tagged for code in our selector and lets you raise its reasoning; GPT-6.1 Sol scored 1481 on the arena.ai Text Arena versus 1477 for Sonnet (October 27, 2026). For programming, start with Sonnet.
How do I change Claude Sonnet 5.5's reasoning level on NeverNo?
Choose Claude Sonnet 5.5 in the model selector, then open its Reasoning setting in the selector and pick Adaptive or High. The choice applies to your next messages and can be changed at any time.