Quick Answer
Claude Sonnet 5.5 is Anthropic’s faster, lower-cost model for well-scoped work such as bug fixes and document creation. Anthropic lists unchanged API rates of $2 per million input tokens and $10 per million output tokens, while claiming faster output and lower per-task use. Developers should test Sonnet 5.5 on representative workloads before switching production systems.
Key Takeaways
- Anthropic released Claude Sonnet 5.5 on September 28, 2026.
- Claude Sonnet 5.5 is positioned for well-scoped tasks, including bug fixes and creating documents, slides, and spreadsheets.
- Anthropic lists API pricing of $2 per million input tokens and $10 per million output tokens.
- Anthropic says Claude Sonnet 5.5 produces outputs more than 30% faster than Sonnet 5.
- Amazon Bedrock offers Claude Sonnet 5.5 through the Global CRIS inference profile.
What is Claude Sonnet 5.5?
Claude Sonnet 5.5 is Anthropic’s second model in the Claude 5.5 family and a faster, lower-cost complement to Claude Opus 5.5. Anthropic released the model on September 28, 2026, and positioned it for well-scoped everyday work rather than the most complex assignments requiring careful judgment. Anthropic’s Claude Sonnet 5.5 announcement describes the model’s intended role and performance claims.
Claude Sonnet 5.5 is meant to handle tasks where a user can define a clear goal and evaluate the result. Anthropic specifically identifies bug fixes, documents, slides, and spreadsheets as suitable uses. This matters because model selection is increasingly a cost and speed decision, not only a question of whether an AI system can produce an answer.
Claude Opus 5.5 remains Anthropic’s option for work that needs more careful judgment, according to the company. Users comparing the two models should treat that distinction as a practical starting point rather than a guarantee that Sonnet 5.5 will be sufficient for every coding or business workflow. Teams should evaluate outputs against their own requirements before relying on any model for consequential work.
Claude Sonnet 5.5 also arrives shortly after the company’s more capable model release. Readers deciding whether to use the faster option can compare its intended role with the earlier Claude Opus 5.5 release, which focused on lower API prices and a larger context window.
How much does Claude Sonnet 5.5 cost?
Claude Sonnet 5.5 costs $2 per million input tokens, $10 per million output tokens, and $0.20 per million cache-read tokens. Anthropic lists the same token rates for Sonnet 5, which means the published API price did not rise with the newer model. Input tokens are the text or data sent to a model, while output tokens are the content the model generates in response.
Anthropic says Claude Sonnet 5.5 typically uses fewer tokens to complete the same work, reducing per-task costs by up to 30%. The company’s claim matters because token pricing alone does not show the final cost of a task. A model that reaches a usable result with fewer generated tokens can cost less even when its listed token rate stays unchanged.
| Claude model | Primary positioning | Published pricing detail | Practical consideration |
|---|---|---|---|
| Claude Sonnet 5.5 | Well-scoped everyday tasks | $2 input, $10 output, and $0.20 cache-read per million tokens | Test whether lower token use reduces total task cost. |
| Claude Opus 5.5 | Complex work requiring careful judgment | Not covered in the Sonnet 5.5 announcement details | Use when task complexity matters more than fast routine output. |
Claude Sonnet 5.5 pricing is most useful as a planning figure, not a complete budget forecast. Actual spending depends on the amount of input, output, and cached context a workflow uses. The practical response is to measure a representative set of prompts before moving a high-volume application to the new model.
How much faster is Claude Sonnet 5.5 than Sonnet 5?
Claude Sonnet 5.5 generates outputs more than 30% faster than Sonnet 5, according to Anthropic. The company also says the model typically needs fewer tokens to complete the same work, which can reduce both completion time and per-task expense. Faster output can improve interactive experiences where users are waiting for code, written material, or structured business documents.
Claude Sonnet 5.5 performance will still vary by prompt size, tool use, workflow design, and the amount of output requested. A short request for a bug fix does not create the same demand as a long process involving documents, spreadsheets, or multiple revisions. The company’s percentage is therefore useful for comparison, but it is not a promise that every request finishes 30% faster.
Claude Sonnet 5.5 may be especially relevant for development teams using AI assistance in repeated tasks. Anthropic positioned the model for bug fixes, while existing tools such as parallel coding work show why completion speed can matter when an AI system is part of a larger development process. Human review remains necessary because a faster response does not establish that a proposed code change is correct or secure.
How did Claude Sonnet 5.5 perform on Anthropic’s evaluations?
Claude Sonnet 5.5 scored 70.6% on Terminal-Bench 4.0, compared with 10.3% for Sonnet 5 and 66.4% for Opus 5.5, according to Anthropic’s self-reported coding evaluation. Anthropic also reported a 55.5% score on CursorBench 4.0 and an 80.1% partial-credit score on OSWorld 2.1 computer-use testing.
Claude Sonnet 5.5’s reported scores suggest that Anthropic expects the lower-cost model to handle a broad range of coding and computer-use work. Terminal-Bench evaluates tasks in a terminal environment, while computer-use evaluations assess whether a model can work through tasks on a computer. These measurements are useful indicators, but they do not replace testing on a company’s own codebase, data, permissions, and review process.
Anthropic’s benchmark results are self-reported, and independent testing may produce different conclusions. The most sensible interpretation is that Sonnet 5.5 has a strong company-reported performance case for routine technical work, while deployment decisions should depend on accuracy, reliability, cost, and error handling in real workloads.
What safety controls does Claude Sonnet 5.5 include?
Claude Sonnet 5.5 is Anthropic’s first Sonnet model released with cyber safeguards and fallbacks comparable to those used on the company’s most capable models. Anthropic says routine software development and most life-sciences work are unaffected by those controls. The company’s design signals that stronger model capability requires more attention to how a system handles sensitive requests.
Claude Sonnet 5.5 safeguards matter because AI systems can be used in workflows that touch code, systems, scientific information, and business data. Guardrails can reduce certain misuse risks, but they do not remove the need for access controls, code review, logging, and security testing. Organizations should avoid giving an AI model unnecessary credentials or unrestricted access to production systems.
Claude Sonnet 5.5 users should also avoid entering confidential customer information, secrets, private keys, or regulated records unless their organization has approved the relevant data handling arrangement. Recent attention to AI agent risks, including the FTC’s consumer-risk investigation, reinforces why convenience should not override data governance. Stop and consult a security or compliance team before connecting an AI model to sensitive internal systems.
Where is Claude Sonnet 5.5 available?
Claude Sonnet 5.5 is available through Claude products and through Amazon Bedrock. Claude’s consumer-product release notes confirm the model launch, while AWS announced same-day availability for Claude Platform on AWS and Amazon Bedrock. Claude’s release notes provide Anthropic’s product-side confirmation of the release.
Amazon Bedrock identifies the model as global.anthropic.claude-sonnet-5-5 and makes it available through the Global CRIS inference profile. AWS’s Claude Sonnet 5.5 availability announcement sets out the model identifier and deployment details.
Claude Sonnet 5.5 availability through AWS matters for organizations that already use Amazon’s managed AI infrastructure. The Bedrock identifier is relevant only for developers configuring that platform, while other users should use the Claude product access offered to their account. Organizations should confirm regional access, account permissions, and applicable data policies before changing a production integration.
Who should use Claude Sonnet 5.5 instead of Claude Opus 5.5?
Claude Sonnet 5.5 is the more appropriate choice for users whose work is well-scoped and benefits from faster responses and lower per-task costs. Anthropic specifically places bug fixes, document creation, slide creation, and spreadsheet work in that category. The model’s published pricing and claimed token efficiency make it a practical option for routine, repeated workloads.
Claude Opus 5.5 is the more appropriate choice when a task requires careful judgment and greater complexity handling, based on Anthropic’s positioning. That distinction does not mean Sonnet 5.5 cannot perform difficult work, nor does it mean Opus 5.5 is necessary for every demanding prompt. The right selection depends on whether the task has a defined scope, how costly errors are, and whether a human can reliably review the result.
Claude Sonnet 5.5 users should begin with a limited evaluation that compares quality, speed, token use, and failure cases against their current workflow. Developers building AI features should also establish a human approval path for code changes, customer-facing content, or decisions that affect users. The practical goal is to use the faster model where its speed and cost benefits are measurable without lowering the required standard of review.
What should developers test before adopting Claude Sonnet 5.5?
Claude Sonnet 5.5 developers should test 4 areas before adopting the model: output quality, task completion time, token consumption, and unsafe or incorrect behavior. These checks show whether Anthropic’s claimed speed and cost improvements hold for the prompts, data formats, tools, and review standards that matter to a specific product.
- Run Claude Sonnet 5.5 against a representative set of existing tasks, including common requests and difficult edge cases.
- Measure input tokens, output tokens, cached context use, and total task cost for each completed task.
- Compare response time and result quality with the model currently used in the workflow.
- Review incorrect code, unsupported claims, incomplete documents, and actions that require human approval.
- Limit access permissions before connecting Claude Sonnet 5.5 to internal tools, customer data, or production systems.
Claude Sonnet 5.5 testing should include a clear stop line. Stop the rollout and contact the relevant platform, security, or compliance team if the model exposes sensitive data, makes changes outside its intended permissions, or produces errors that human reviewers cannot confidently detect. A faster model is useful only when the surrounding system can contain mistakes before they reach users or production infrastructure.
FAQ
When did Anthropic release Claude Sonnet 5.5?
Anthropic released Claude Sonnet 5.5 on September 28, 2026. The model is the second release in Anthropic’s Claude 5.5 family and is positioned as a faster, lower-cost complement to Claude Opus 5.5.
How much does Claude Sonnet 5.5 cost?
Claude Sonnet 5.5 costs $2 per million input tokens, $10 per million output tokens, and $0.20 per million cache-read tokens. Anthropic says the listed token rates match Sonnet 5, while lower token use can reduce per-task costs by up to 30%.
Is Claude Sonnet 5.5 faster than Sonnet 5?
Claude Sonnet 5.5 produces outputs more than 30% faster than Sonnet 5, according to Anthropic. Actual response times still depend on prompt length, output size, tool use, and the specific workflow.
What tasks is Claude Sonnet 5.5 designed for?
Claude Sonnet 5.5 is designed for well-scoped everyday tasks, including bug fixes and creating documents, slides, and spreadsheets. Anthropic positions Claude Opus 5.5 for more complex work that requires careful judgment.
Can developers use Claude Sonnet 5.5 through Amazon Bedrock?
Claude Sonnet 5.5 is available through Amazon Bedrock using the global.anthropic.claude-sonnet-5-5 model identifier. AWS says the model is offered through the Global CRIS inference profile, subject to applicable account access and deployment requirements.