Use Claude Opus 5 in Chrome
Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work. One shortcut on any page, your own OpenRouter key, provider prices.
Get it for $49Is there a revision history on this page?
Yes, under the title. It lists four revisions.
Claude Opus 5
What changed in this RFC since the last revision?
Two things. The retry section now caps attempts at five instead of leaving the count open. And the deprecation date moved from March to June. The rest of the text reads the same.
Claude Opus 5 4,312 in, 96 out
What Claude Opus 5 is good at
Three jobs it does well from the launcher, and what comes back when you run them.
Ask About Page {question} Summarize {selection} Translate To {language} Fix Spelling and Grammar {selection} Rewrite As {tone} Simplify Text {selection} Ask About Page Claude Opus 5 Which plans does this clause cover?
The clause you asked about applies to annual plans only.
Based on {tab-text}, answer {question}
Dense specs and policies
Open a dense spec in a tab and ask the question you would otherwise spend an hour on.
What it can read
Every tool reads. Turn any off in settings.
Ask About Page Summarize Translate To One summary covers the whole report, and the numbers stay in place.
Claude Opus 5
Long reports in one pass
A million-token window means a whole report goes in at once instead of in four passes.
The diff renames the field but leaves two call sites on the old name.
Claude Opus 5 Reviewing a pull request
Sit on a pull request page and ask what the diff gets wrong.
What it costs in your browser
Pay OpenRouter per token. UtilEngine adds nothing.
Claude Opus 5 bills $5 for a million input tokens and $25 for a million output tokens. A page of text is a few thousand tokens, so most of what you do in a browser costs cents, not dollars.
At list price a $20 month buys about 700 long-article summaries. You are not buying a month, though. You pay for the tokens each job uses, and the rest of your OpenRouter balance just sits there.
The extension asks OpenRouter for the fastest route, which can be a provider's priority tier rather than the one this receipt is priced on. When that tier wins, the same three jobs cost about twice what you see here, and your OpenRouter activity page shows what you were actually charged.
Claude Opus 5 or Claude Sonnet 5
Two models from the same list, side by side, so you can put the expensive one where it earns its price.
Pick it for the questions that need every token
Pick it for the page work you do all day
Switch between them per command. See how
Switch models mid-chat
Set a default for chat, another for Ask AI, and a different one for any command.
77 models, one key
Seven providers in the same picker. OpenRouter bills each one at its own rate.
How to use Claude Opus 5 in Chrome
A free key, one paste, and the model shows up everywhere the AI runs.
Create an OpenRouter key
One free key reaches Claude Opus 5 and every other model in the list.
Provide API Keys Paste it in AI settings
Run Provide API Keys, paste once, and the key stays in your browser's extension storage.
Models Pick Claude Opus 5
Set it for chat, for Ask AI, or for a single command. Switch again whenever you like.
Claude Opus 5, answered
Is Claude Opus 5 available in UtilEngine today?
Yes. It sits in the model list as claude-opus-5 and calls anthropic/claude-opus-5 through OpenRouter with OpenRouter's :nitro speed routing, which the extension uses for every Anthropic model.
What does Claude Opus 5 cost through UtilEngine?
Nothing beyond the one-time $49 for the extension. OpenRouter lists Opus 5 at $5 per million input tokens and $25 per million output, which puts a long-article summary near three cents. The extension routes for speed, so a faster provider can serve the request at up to $10 per million in and $50 out. Each reply shows the tokens it used.
Do I need an Anthropic account?
No. One OpenRouter key reaches Opus 5 and the other 76 models in the list. There is no direct Anthropic key and no second bill.
Can I use Opus 5 for one command and a cheaper model for another?
Yes. Each AI command stores its own model, so Ask About Page can run Opus 5 while Fix Spelling and Grammar stays on the cheap default.
Does the AI act on pages?
No. Every tool it has reads, and nothing writes. It can read page text, your selection, tabs, history, bookmarks and downloads, and each call shows as a chip in the thread. It never clicks, types or submits a form.
Claude Opus 5, one keystroke away
Chat, Ask AI, and your own commands on any page, in a launcher with 50+ built in. One payment, yours forever.
Get it for $49One-time payment. 14-day refund, no questions asked.