Skip to content
Anish Gandhi Claude Opus 5.5 Connect on LinkedIn

← All guides · checked against Anthropic's docs on

Opus 5.5 in Cowork

Nothing breaks, and Anthropic says Cowork needs no changes from you. Opus 5.5 does start work sooner, so how you describe a task matters a little more.

In 30 seconds

  • Say where to look. It gets to work quickly. Ask it to check the relevant emails, files and tabs before it changes anything.
  • Another model may step in. A few sensitive steps are handled by an older model, with a notice saying so.
  • Better finished work. Fewer wrong figures, and spreadsheets and slides that need less editing.
  • More room. Higher five-hour , and a spare .

What changes for you

Open How to for where to click. Pick the model you used before to hide what does not apply to you.

Before Opus 5.5, I used

  1. Changes quietly

    It starts sooner, so say where to look

    Anthropic says Opus 5.5 tends to get to work quickly. On a loosely described task across your email, documents and spreadsheets, it can miss something the task did not point to, like a rule on another spreadsheet tab.

    How to
    1. In the task, ask it to look through the relevant emails, documents and spreadsheet tabs before it changes anything.
    2. Name the sources you know matter, like an old email thread or a note on a customer record.
    3. Expect a few more steps when you do, which use a little more of your .

    Source: Prompting Claude Opus 5.5: multi-app work

  2. Changes quietly

    Some steps are handed to another model

    If part of a task looks like security testing, risky biology or building other AI models, an older model handles it instead. A notice says so, and the reply is labelled with the model that wrote it.

    • Coming from Opus 4.8 Opus 4.8 is the model that security work is handed to, so you may see it again.
    • Coming from Opus 5 On Opus 5 only security work was handed on, to Opus 4.8. Biology and AI-building work are new, and they go to Opus 5.
    • Coming from Fable 5.1 Fable 5.1 hands on the same kinds of work, to the same models.
    How to
    1. After a switch, the session stays on the older model. Pick Opus 5.5 again when you want it back.
    2. To be asked instead: Settings > Capabilities, turn off . A flagged step then pauses, so you can reword it.

    Source: Why Claude switched models (Help Center)

  5. Good news

    Better at using apps on your screen

    On Claude Desktop, Cowork can operate apps through screenshots and clicks (a beta). Anthropic says Opus 5.5 does this more reliably, and reads charts and screenshots more accurately.

    • Coming from Opus 5 At its default effort it matched the success rate Opus 5 reached only at a much higher setting.

    Source: Prompting Claude Opus 5.5

  6. Good news

    More room in your five-hour limit

    Anthropic raised the five-hour on Pro, Max, Team and seat-based Enterprise plans at launch and gave subscribers a spare . Every step of a task uses some of it, so tasks use more than chat.

    How to
    1. Group related work into one task instead of several small ones.
    2. Check what is left in Settings > Usage. The reset button is there too, in a browser or Claude Desktop.

    Source: Get started with Cowork (Help Center)

  8. Good to know

    Cowork is joining chat

    Anthropic is rolling out a Claude app with no separate Cowork option: you ask, and Claude decides whether to answer or run a task. It is reaching Pro and Max first. On Enterprise, admins turn it on.

    How to
    1. If your message box no longer shows Chat and Cowork options, you have the new version. Everything on this page still applies to the tasks you give it.

    Source: Claude Cowork is now just Claude (Help Center)

Sources

Every fact on this page comes from Anthropic's own documentation, checked on 23 Sep 2026, unless it is labelled as a tester's report. Numbers from testers come from one small team with early access. Treat them as early impressions.

Anthropic's documentation