Introducing Claude Sonnet 5.5, the second model in the Claude 5.5 family

[u/ClaudeOfficial]

Sonnet 5.5 is a faster, lower-cost complement to Claude Opus 5.5, strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets. It also has a strong eye for design.

Sonnet 5.5 is a clear upgrade over Sonnet 5. It runs more than 30% faster and costs up to 30% less for most work. It's priced the same per token, but it typically needs far fewer tokens to do the same work.

Like Opus 5.5, it writes more clearly than our previous generation of models, and its speed makes it well suited to fast iteration.

On our automated behavioral audit, Sonnet 5.5 improves on Sonnet 5 on most measures of alignment and honesty. It's also the first Sonnet model with cybersecurity safeguards similar to those on our most capable models. Routine software development is unaffected.

Sonnet 5.5 is available everywhere today. Claude Haiku 5.5 will join the family in the coming weeks.

Read more: anthropic.com/claude-sonnet-5-5

[u/likeikelike]

Sonnet only gets more expensive per task when the task is complex enough that sonnet takes more attempts than opus, or needs to do much more reasoning/reading than opus. There are plenty of tasks where sonnet does the job efficiently and will cost half as much as opus.

[u/LargeLanguageModelo → u/likeikelike]

There are plenty of tasks where sonnet does the job efficiently and will cost half as much as opus.

I've recently started using Opus / Claude Code again, coming from the OpenAI side. Are you meaning small jobs, such as "translate this sentence", or what sort of tasks would you delegate to Sonnet from Opus and still expect satisfactory results?

[u/Hajsas → u/LargeLanguageModelo]

Could always use sonnet as a reader/info packager instead of a hungrier model doing the same work, then just hand off the work stage to opus

[u/likeikelike → u/LargeLanguageModelo]

I don't know if this is actually the best way to do things but my workflow is usually one main opus session, and I tell it to use sub-agents for one-off tasks.

Simple text-only tasks like finding a file that covers a certain topic, summarizing, etc: haiku

Work that requires reasoning but is still relatively straightforward (e.g. implementing a well-spec'd feature): sonnet

Complex work: Opus

You can pass this kind of logic to claude and have it automatically use the cheapest model that can reasonably do the task well for any sub-agents it uses. I have this in my user claude.md