When did Anthropic release Claude Sonnet 5.5?

Anthropic released it on September 29, Japan time (early morning), according to the announcement.

How does Claude Sonnet 5.5 compare with Claude Opus 5.5?

On some coding benchmarks it outperforms the higher-tier Claude Opus 5.5, the announcement says. It is also the first Sonnet model offered with the same level of safety measures as the higher-tier model.

What changed from Claude Sonnet 5?

Processing speed and cost efficiency improved over Claude Sonnet 5, according to the announcement.

Large Language ModelsTop Companies' AI MovesAI Business & IndustryTop Companies AIOct 8, 2026Oct 9, 2026, 06:31 JST

Claude Sonnet 5.5 lands on Exabase AI, tops Opus on coding

Send on LINE

3 Key Points

What happened
Exa Enterprise AI began offering Anthropic's Claude Sonnet 5.5, released September 29 Japan time, on its enterprise generative AI service Exabase AI. It is faster and cheaper than Claude Sonnet 5 and beats Claude Opus 5.5 on some coding benchmarks.
Why it matters
Enterprise teams using Exabase AI get a mid-tier model that, by the company's account, matches a higher-tier model on some coding tasks, and it is the first Sonnet to carry the same safety measures as the top-tier model.
What to watch
Exa Enterprise AI says it is starting to offer the model, following Anthropic's September 29 release.

WHO IT HITSEnterprise IT and business teams that use Exabase AI for coding, long-running agent tasks, and document or slide creation are the direct audience — the body says those are the workloads where Claude Sonnet 5.5 is strong. Procurement and security teams may note that this is the first Sonnet released with the same safety measures as the higher-tier model.

Not sure about something? Ask the AI

Questions and answers are published on this page.

Summaries like this, in your inbox every morning.

Get news like this every morning, free

Context & Analysis

The announcement positions Claude Sonnet 5.5 as a mid-tier model that narrows the gap with Anthropic's top-tier offering. Exa Enterprise AI says that in some coding benchmarks, Sonnet 5.5 outperforms Claude Opus 5.5, and that the model also handles long-running agent tasks and document or slide creation well.

Speed and cost efficiency are the stated gains over Claude Sonnet 5, which matters for buyers weighing how far an AI budget stretches on everyday business work. The announcement also notes that, because of the model's strength in cybersecurity, this is the first Sonnet release given the same safety measures as the higher-tier model.

Exabase AI, offered by Exa Enterprise AI under Exa Wizards, cites the top share of the corporate generative AI market in a 2024 fiscal-year vendor survey by Fuji Chimera Research Institute. The service was renamed from 'exaBase 生成AI' to 'Exabase AI' in July 2026, according to a footnote in the announcement.

FAQ

When did Anthropic release Claude Sonnet 5.5?: Anthropic released it on September 29, Japan time (early morning), according to the announcement.
How does Claude Sonnet 5.5 compare with Claude Opus 5.5?: On some coding benchmarks it outperforms the higher-tier Claude Opus 5.5, the announcement says. It is also the first Sonnet model offered with the same level of safety measures as the higher-tier model.
What changed from Claude Sonnet 5?: Processing speed and cost efficiency improved over Claude Sonnet 5, according to the announcement.

AI news that matters for your work, delivered every morning.

Pick your industry and the AI tools you use, and get news related to your work every day.

Get it free

Free · 30 seconds with Google · unsubscribe anytimeWhat is AIToday? →

Ask AI

Ask AI anything about this article. The AI reads this article, earlier AIToday articles, and Wikipedia, and cites its sources. Q&As are published on this page for other readers too.