What is a Grammarly alternative that knows my work?
The short version: Opsis writes your next line wherever you type: Slack, Gmail, Outlook, Teams, Notion, Google Docs and AI chats like Claude and ChatGPT. Press Tab to keep it. It can also draft a whole reply from a few notes, using facts from your own work: what's on your screen, the apps you connect (Gmail, Calendar, Drive, Slack, Notion, GitHub, Linear, Outlook) and your history. If you use Grammarly to polish sentences, Opsis does a different job: it helps you start and finish the message, with the right facts in it.
Grammarly is strong at spelling, grammar and tone on text you already wrote. Opsis isn't a proofreader. Some people would run both, since one tidies a sentence and the other produces the sentence with the right date and name in it.
How it compares.
Grammarly and Opsis compared, as of November 2026
| Tool | Main job | Where it works | Knows your work |
|---|---|---|---|
| Opsis | Writes your next line and drafts replies from notes. Tab to keep. | Slack, Gmail, Outlook, Teams, Notion, Google Docs, AI chats. Mac and Windows. | Yes: screen, connected apps and history. |
| Grammarly | Spelling, grammar, clarity and tone suggestions, plus AI writing help. | Mac, Windows, browser, mobile. | Superhuman Go, from the same company, adds an assistant that works from what is on your screen. Details depend on plan. |
| HyperWrite | AI autocomplete and drafting that its site says learns your style. | Browser-based. | Vendor claim, not tested. |
| LanguageTool, QuillBot | Grammar checking and rewriting. | Browser and apps. | No. |
Swipe the table to compare
Figures and shutdown dates come from the sources at the bottom, or from this site's own product copy. We don't invent competitor features.
Who it's for.
People who write many work messages a day and spend more time finding the right fact than fixing the grammar.
Your data.
Opsis only follows the apps you share. Private windows and password managers are never recorded. When assistance is on, the text it needs is processed in the cloud with your consent, encrypted in transit and at rest, with zero data retention at our AI providers. Opsis isn't a screen recorder. You can pause, disconnect an app or delete your history whenever you like. Read the privacy policy · How Opsis handles data.
Proofreading versus drafting
A proofreader assumes you already know what to say. A lot of work writing is the other problem: you know roughly what to say but need the date, the number, the name or the earlier decision. That is the gap Opsis targets.
Where Grammarly is still the better pick
For long documents, formal writing, or anyone who wants polished grammar checking everywhere, Grammarly is the more mature tool. Opsis does not check your spelling line by line.
FAQ
Is Opsis a Grammarly replacement?
Not a full one. It does not proofread. It writes and finishes messages using your work context. Some people keep both.
Does Opsis work in the same apps as Grammarly?
It covers Slack, Gmail, Outlook, Teams, Notion, Google Docs and AI chat windows on Mac and Windows. Try the free version in the app you use most.
How much does Opsis cost?
Free to start. Pro is $15 a month.