Check an AI draft in Word, and use AI without leaking the details.

Check the draft before it goes out

Check reads the whole document, or only what you selected, with the same rules as the site's own tools:

• Phrases that sound machine-made. Filler openings such as "Certainly", AI-favorite words such as delve and seamless, long dashes and the other habits readers notice. Click a phrase and Word selects it. The same rules as the Robot-Speak Checker.
• Claims to check. Every sentence with a number, a date, a quote or a named source, riskiest first, because these are the details AI makes up most often. The same rules as the Fact Check List.
• Markdown and blanks. Stars and pound signs left over from a chat, and text such as [insert company name] that is easy to miss in a long document.
• Private details. Email addresses, phone, card, bank and ID numbers, so nothing goes out by mistake.
• Links to open. AI writes links that look right and lead nowhere.

Highlight all marks every finding in yellow, and Clear highlights takes the marks away again.

Use ChatGPT or Claude on a client document, safely

Safe for AI takes the selection or the whole document and swaps every name, email address, phone and account number for a placeholder such as [NAME_1], the way Safe Paste does. You say what the AI should do, copy the text or open ChatGPT or Claude with it, then paste the answer back into the pane. The real names and numbers go back in, and one press puts the result in the document where your cursor is.

Score a prompt where you wrote it

Many people draft their prompts in a document first. Select one, open Prompt, and it is scored out of 10 on the ten checks, with the questions the AI would otherwise guess at. Rebuild adds the missing parts as blanks to fill, as the Prompt Improver does.

How to add it

Until it is listed in Microsoft AppSource, Word adds it from a small file that tells Word where the add-in lives.

1. Download the add-in file (manifest-word.xml).
2. Open a document in Word on the web, at office.com.
3. On the Home tab choose Add-ins, then More Add-ins. In the window that opens, choose My Add-ins, then Upload My Add-in, and pick the file. The wording can differ slightly between versions of Word.
4. Check draft appears on the Home tab. Press it to open the pane.

At work, your IT team can add it for everyone at once from the Microsoft 365 admin center (Settings, Integrated apps, Upload custom apps) with the same file. That is also how it reaches Word on Windows and Mac before the AppSource listing.

Private by design

Every check runs in the pane, inside Word. The add-in sends nothing you write to thinkhard.si or anyone else and stores nothing. It reads the document only when you press a button, and changes it only when you ask: a highlight you can clear, or text put in where your cursor is. Text goes to ChatGPT or Claude only when you press their button, with the placeholders in place of the details you kept ticked. The full detail is in the privacy policy.