Developers with Visual Studio subscriptions can access the "Office 2021 Proofing Tools Kit" for development and testing purposes.
Finding a true, standalone "offline installer" specifically for Office 2021 Proofing Tools is significantly harder than it was for previous versions (like 2013 or 2016). Microsoft has moved away from downloadable .exe language packs for retail versions, pushing users toward the "Language Accessory Pack" model or Configuration Profiles.
Verdict: It is possible to install proofing tools offline, but it requires technical effort (using the Office Deployment Tool). The "easy" one-click offline installers largely no longer exist officially. office 2021 proofing tools offline installer
Before diving into the offline installer, let’s clarify what "Proofing Tools" actually include. When you install Microsoft Office 2021 normally, you get proofing for the language version you installed (e.g., English). However, if you need to write a document in French, proofread an email in Spanish, or check spelling in German, you need the additional Language Accessory Packs—commonly called Proofing Tools.
These tools consist of:
Without these tools, Office 2021 will flag correctly spelled foreign words as errors, or worse, ignore errors entirely.
Download the Office Deployment Tool from Microsoft (requires internet once to fetch the tool). Developers with Visual Studio subscriptions can access the
If you manage 500 computers, downloading 500 separate copies of a language pack over the internet is inefficient and bandwidth-heavy. With the offline installer, you download once, copy to a network share, and deploy via Group Policy or SCCM.