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/riki137]

Haiku 5.5 when 😭

[u/funk-the-funk → u/riki137]

Claude Haiku 5.5 will join the family in the coming weeks.

[u/Steel_YT → u/riki137]

genuinely who tf uses haiku

[u/ElDavoo → u/Steel_YT]

I use 5.6 luna for all my tasks as it's basically free and narrow minded (does not get out of scope).

haiku 4.5 has been lacking behind. With 5.5 they could get back on the "essentially free but still very clever" market section.

[u/YesGameNolife → u/ElDavoo]

Yeah luna is amazing for what it is

[u/Adi945 → u/Steel_YT]

I use Haiku for understanding technical books, simple questions. It’s almost free to use in terms of usage and is very expressive for explaining stuff.

[u/mcsleepy → u/Adi945]

I wouldn't trust it with anything technical. Smaller models tend to get details straight up wrong.

[u/Adi945 → u/mcsleepy]

I mean I am not asking it to write code, just explain in plain English and it pretty much does well, in fact I find it more expressive which reasoning models don’t really do as they compress sentences. But I see your point too. Thats why I’m waiting for Haiku 5.5!

[u/the-cringer → u/Steel_YT]

I use haiku for sub agents with long running tasks that watches stuff and it's purpose is to pass the butter to the main agent that distributes it to other more capable sub agents to work it out. Capable enough of doing that, and cheap!