On September 28, Anthropic released Claude Sonnet 5.5. If you use Claude for everyday work, like emails, documents, or making sense of a confusing letter, this is the update that touches you most. And the short version is good news: you don't have to do anything. Claude just got faster, and better at the stuff most of us actually use it for.

Here's what changed, in plain English, and 3 things worth trying this week.

What is Claude Sonnet 5.5?

Claude comes in a few versions, which Anthropic calls models. Think of them like car trims: same car, different engines. Sonnet is the everyday one, quick and capable, and the one most people talk to. Opus is the heavier one for harder, longer jobs. A new Opus, Opus 5.5, came out just a week earlier, on September 22.

Sonnet 5.5 replaces Sonnet 5 as the new everyday model.

What's new in Claude, in plain English

  • It's faster. Anthropic says more than 30% faster than Sonnet 5. You'll notice it on long answers.
  • It's better at finished work. Anthropic says it's strongest at everyday tasks and at making polished documents, slides and spreadsheets. So less "here's a rough draft" and more "here's something you can actually send."
  • Its writing is clearer. Early testers called it a more natural conversational partner, which matters if you use Claude to help you write.
  • It reads pictures better. Screenshots, photos of documents, a chart someone emailed you.

How to check you're using it

Look at the model name near the box where you type your message. That's Claude's model menu. If it says Sonnet 5.5, you've got it. If not, click it and pick Sonnet 5.5 from the list. New models sometimes roll out over a few days, so if you don't see it yet, check back.

3 things to try this week

  1. Turn messy notes into a clean page. Paste in your notes from a meeting or a phone call and ask: "Turn this into a one-page summary I can send to my boss."
  2. Make a simple spreadsheet. Paste a list, like monthly bills or a to-do list, and ask Claude to turn it into a spreadsheet with totals.
  3. Decode a confusing letter. Take a photo of an insurance letter or a bill and ask, "What is this actually saying, and do I need to do anything?" Cover up account numbers first.

None of these are new tricks. They just work better now.

Claude Sonnet 5.5 vs Opus 5.5: where it stops

Anthropic is upfront that Opus 5.5 is still the stronger model for complex, open-ended work: a long report, a tricky decision with lots of moving parts. If Sonnet's answer feels thin on something big, try the same question with Opus, if your plan includes it.

And one thing no update changes: Claude can still get things wrong. Check the numbers, names and dates before you send anything that matters.

The takeaway

Claude Sonnet 5.5 is a quiet upgrade to the Claude most people already use. It's faster, it writes more clearly, and it's better at documents and spreadsheets. You don't need to learn anything new. Just use it for real tasks from your own day, and notice what comes back better.

Want to see those 3 tasks done start to finish? That's exactly what I do over on YouTube at @DoWithClaude: one simple task at a time, in plain English.