I was about to open the Claude in Chrome side panel to look at an ad console when I noticed a tab at the far end of the bar: a client's invoice PDF, still open from the morning.
The panel wasn't going to be opened on that tab. I stopped anyway, because I realized I didn't know exactly which tabs Claude can see.
So I reread the official help and settled on a short routine. This post is that routine, plus what I could confirm about how much gets read.
What gets read
The safety page says Claude takes a screenshot of the active tab and can't filter sensitive content out of it. It also advises against opening the side panel on sensitive pages.
In other words, what's read is how the front tab looks. However carefully you set permissions, whatever is visible on the front screen is what gets passed along.
I covered permissions in a separate post on permission modes and the always-allow line. That one is about what Claude may do. This one is about what you show it first.
Three checks before opening the panel
I run the same three every time.
- Is the front tab a screen I need for today's task?
- Are there tabs in the same window that show invoices, statements, email, or someone else's personal data?
- Will I switch tabs before the task is done?
The third is easy to miss. If I move to another tab mid-task, that tab may become the next thing read, so I check where I'm going before I start.
Three buckets
- Show: today's admin screen, or my own published site. Use as is.
- Close: invoices, client correspondence, anything with other people's data. Close before starting.
- Another window: banking, medical, government. Open these in a different browser profile.
Closing is the cheapest step, and it was the one I'd skipped.
Keep sensitive accounts in a separate profile
The help pages recommend a browser profile with no access to sensitive accounts such as banking, healthcare, or government. They also strongly advise against using Claude in Chrome to manage financial accounts, handle legal documents, or process medical information.
I took that literally. I keep a work profile and a personal profile, and the extension is installed only in the work one. The personal profile doesn't have it at all.
A setup where sensitive things can't appear lasts longer than a habit of remembering to check. There will be a tired evening when I forget.
Checking what you've already allowed
You can review which sites carry an "always allow" from the extension icon: open the three-dot menu in the side panel, then Extension settings, then the Permissions page. It lists your approved sites and a permission history, and each one can be revoked.
I put this screen next to the panel habit. Looking back, there were a few times I'd forgotten granting something until I saw the list.
On Team and Enterprise plans, admins can set an allowlist of approved sites or a blocklist that applies no matter what a user allows. That doesn't apply to me, but if you're adopting this at work, ask how tightly your admin has it set.
The routine as a note
I paste three lines at the top of my work notes. They aren't judgment; they're only there to remind me of the order.
```text [ ] Is the front tab today's task screen? [ ] Any invoice, statement, or someone else's data in this window? [ ] Checked the tab I'll switch to mid-task? ```
You don't have to tick them. Reading them before opening the panel is enough to turn up a tab or two I'd forgotten to close.
Things that won't happen even with permission
The help lists actions Claude won't take regardless of permissions: purchases and financial transactions, creating accounts, handling card or ID data, and following instructions found in web pages or emails.
On prompt injection, the official wording is that the risk is "not zero." I read that list as a last safety net, not as something to lean on. Keeping those situations from arising is my job.
One thing to do next
Before your next session, look along the tab bar once and close whatever can be closed. Splitting profiles can wait until after that.
I decide what is shown; what happens after that, I leave to Claude. As an indie developer working in an admin console most days, this is the order I keep, and I'd rather not trade it away.