No door is open. Pick one in the hallway.
What it is, and is not
I
Does Claude watermark text?
Yes. Anthropic watermarks text Claude generates so a holder of the key can estimate whether Claude was involved. The method is a version of SynthID-Text: at the many points where several next words would be equally good, the watermark changes only the source of the randomness used to break the tie. Nothing is inserted. A reader cannot see it.
What it is
- A keyed pattern in low-stakes word choices, undetectable to readers.
- No hidden characters, no extra tokens, no added cost, no practical quality impact.
- A probability that rises with passage length, not a yes-or-no stamp.
- A detection API in private preview for obligated organizations, with access planned to expand.
What it is not
- Not a plagiarism detector. It says nothing about copying another author’s work.
- Not person-traceable. Anthropic says it carries no identifying information and cannot be traced to a person, organization, or chat.
- Not proof of human authorship, and it cannot separate “Claude wrote this” from “Claude heavily edited this.”
- Not the same as stylistic AI-detection software such as Pangram, which does not hold Anthropic’s key.
Source: How Claude's text watermark works · Anthropic · Authorship, bylines, and disclosure norms sit with the writing site, not this how-to. Claude Writes
Paid plans, now GA
II
Is Claude in Chrome generally available?
Yes. Claude in Chrome is generally available on every paid Claude plan. It is a Chrome extension that can see the page you are on and act in it — reading, typing, clicking, navigating, and filling forms with your existing logins — so Claude can reach internal dashboards, legacy tools, and vendor portals that have no connector.
What it is
- Generally available on every paid Claude plan, out of the 2025 pilot.
- Install from the Chrome Web Store. Enterprise admins can allowlist domains.
- Auto-approves actions a safety classifier judges safe and consistent with your request. You can require manual approval in settings.
What it is not
- Not on other Chromium browsers, and not on mobile.
- Not a way to reach local files or other desktop apps. That is still the Claude desktop app.
- Not a reason to leave it unsupervised on banking, health, or send-mail tabs. Prompt injection remains a moving target.
Source: Claude in Chrome is generally available · Claude by Anthropic · Claude Code installation, auto mode, and engineering practice belong there. Everyday Chrome how-to stays here. Claude Ships Code
Drafts, never sends
III
Can Claude send my email?
No. Claude can triage a thread, extract decisions, and draft a reply in your voice. Anthropic’s Gmail connector can search, read, label, and create drafts. It cannot send. Keep the send decision, especially when the message involves money, contracts, hiring, or anything you would not want forwarded as-is.
What it is
- Useful for summaries, action lists, tone repair, and two-draft comparisons (direct vs warmer).
- The Gmail connector drafts in your account. You review and send.
- A good email prompt states relationship, outcome, constraints, forbidden promises, and length.
What it is not
- Not a license to paste confidential HR, legal, or customer data you are not allowed to process in Claude.
- Not a send button. If a workflow requires Claude to fire the message, it is the wrong workflow.
Source: Use Google Workspace connectors · Claude Help Center
PDFs, sheets, output files
IV
Can Claude work a PDF or a spreadsheet?
Yes. Anthropic lists ten upload types, including PDF, DOCX, CSV, and XLSX. Start with an inventory of what Claude can actually see — title, sections, tables, missing pages — before you ask for a summary. Claude can also create .xlsx, .pptx, .docx, and PDF files, on every plan, up to 30MB per file.
What it is
- PDF and office-document analysis with a source-discipline pass: claim, location, unsupported row.
- CSV and spreadsheet work: profiles, formulas, budgets, charts, and reports.
- File creation for Excel, PowerPoint, Word, and PDF when you need a deliverable, not just a chat answer.
What it is not
- Not a substitute for professional review of legal, medical, financial, or audited documents.
- Not magic on a bad scan. If the inventory step reports missing text, stop and fix the file.
- XLSX uploads need code execution and file creation enabled. That is a setting, not a vibe.
Source: Upload files to Claude · Claude Help Center