The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Anthropic had announced two Claude 5.5 models—not three—as of October 7, 2026. Opus 5.5 was announced on September 22, followed by Sonnet 5.5 on September 28. The company said Haiku 5.5 would join the family “in the coming weeks,” which is a future plan, not confirmation of a launch. Anthropic has also filed a confidential draft registration statement for a proposed IPO, but has announced neither a listing date nor offering terms.
Which Claude 5.5 models have launched?
Anthropic’s dated announcements and release notes establish this sequence:
![Claude AI for Beginners Bible: [5 in 1] The Ultimate Guide to Automate Your Work, Save Hours Every Week, and Use AI for Real-World Results](https://m.media-amazon.com/images/I/415+fSJacsL._SL160_.jpg)
As an Amazon Associate I earn from qualifying purchases.
- Claude Opus 5.5: Announced September 22, 2026, as the first model in the Claude 5.5 family. Anthropic positioned it for complex work requiring careful judgment, including coding and professional tasks. Anthropic’s Opus 5.5 announcement.
- Claude Sonnet 5.5: Announced September 28, 2026, as the second model in the family. Anthropic described it as a faster, lower-cost choice for well-scoped everyday work. Anthropic’s Sonnet 5.5 announcement.
- Claude Haiku 5.5: Announced as forthcoming, with Anthropic saying it would join the family “in the coming weeks.” The announcements available by October 7 do not establish that Haiku 5.5 had launched. Anthropic’s Sonnet 5.5 announcement.
Anthropic’s Claude release notes likewise list the Opus and Sonnet announcements on September 22 and September 28. That is why describing Haiku as a third launched model goes beyond the dated evidence.
How do Opus 5.5 and Sonnet 5.5 differ?
| Model | Intended workload | Performance claims | API price reported |
|---|---|---|---|
| Opus 5.5 | Complex work requiring careful judgment, including coding and professional tasks. | Anthropic said it performs at the level of Claude Fable 5.1 on most work, produces output more than 30% faster than Opus 5, and costs 40% less to run than Opus 5. These are company-reported comparisons. Anthropic. | $4 per million input tokens and $20 per million output tokens, as reported by Reuters on September 28, 2026. Reuters. |
| Sonnet 5.5 | Well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets. | Anthropic said it is more than 30% faster and costs up to 30% less for most work than Sonnet 5. The company reported 70.6% on Terminal-Bench 4.0, an agentic coding evaluation, compared with 10.3% for Sonnet 5. These are Anthropic’s figures, not independent test results. Anthropic. | $2 per million input tokens and $10 per million output tokens, as reported by Reuters on September 28, 2026; Reuters said Sonnet’s price was unchanged from its predecessor. Reuters. |
| Haiku 5.5 | Anthropic said it is being built for high-volume, cost-sensitive applications. It had not been confirmed as launched in the announcements cited here. | Not stated in the cited announcement. | Not stated in the cited announcement. |
For readers choosing between the two announced models, the company’s positioning is the clearest distinction: Opus is aimed at more demanding work, while Sonnet targets everyday tasks with defined scope. The speed, cost, and benchmark figures above are Anthropic’s claims; they should not be read as an independent head-to-head evaluation.
#1 Best Overall
Is Anthropic’s IPO confirmed?
No. On June 1, 2026, Anthropic said it had confidentially submitted a draft registration statement on Form S-1 for a proposed IPO. The company said a public offering would depend on SEC review, market conditions, and other factors. It had not set the share count or price. Anthropic put it plainly: “This gives us the option to go public after the SEC completes its review.” Anthropic’s IPO update.
A confidential draft filing is a step toward a possible offering, not confirmation that shares are already trading or that a public listing is scheduled. The cited announcement gives no IPO date or final terms.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Why the lineup and IPO news are being discussed together
The announcements show Anthropic expanding its model family while preparing for the possibility of going public, but they do not establish that the product launches determine whether or when an IPO will happen. Reuters reported on September 28, 2026, that enterprise customers accounted for about 80% of Anthropic’s business, and named Salesforce, Databricks, Goldman Sachs, and Novo Nordisk among its customers. That is Reuters-reported company context, distinct from the model details Anthropic published in its launch posts. Reuters.
Quick Recap
Best Value
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
