The Problem with Cloud-Based Checkers
Tools like Grammarly have become indispensable for many, catching typos and awkward phrases in everything from emails to reports. However, this convenience relies on sending your text to the company's servers for analysis. While these companies have security
measures, this practice creates inherent risks. Your data—which could include confidential business strategies, personal information, or sensitive client details—is exposed to potential data breaches and may even be used to train AI models. For anyone handling proprietary information, this is a significant concern. The good news is that you don't have to choose between privacy and perfection. A growing number of tools allow you to perform powerful grammar and style checks entirely on your own machine.
Hack 1: Self-Host an Open-Source Powerhouse
For those who want the power of a cloud service without the cloud, LanguageTool is the gold standard. It's an open-source grammar, spelling, and style checker that supports over 25 languages. While it offers a public cloud version, its real strength for privacy is that you can run the entire server application on your own computer. Using technologies like Docker or by running it directly with Java, you can create a local server instance. Once it's running, you simply configure the LanguageTool browser extension or LibreOffice add-in to point to your local machine instead of its default cloud address. All processing happens locally, meaning your sensitive documents never leave your device. This is the top choice for developers and organisations needing robust, compliant grammar checking.
Hack 2: Use a Modern, Offline-First Tool
A new generation of writing aids is being built with local processing as a core feature. One of the most promising is Harper, an open-source grammar and spell checker that runs entirely on your device. It’s designed explicitly as a privacy-first alternative and never sends data over the network. Harper is extremely fast because it’s built in the Rust programming language and integrates into popular code editors like VS Code and Obsidian. Another option for technical writers is Vale, a prose linter that focuses on enforcing a consistent style guide, checking for passive voice, and flagging jargon. Like Harper, it runs completely offline and is a standard for many documentation teams.
Hack 3: Supercharge Your Code Editor
If you already spend most of your day in a text editor like Visual Studio Code (VS Code), you can add powerful grammar checking without ever leaving your workflow. The LTeX extension for VS Code brings the full power of LanguageTool to your editor, checking grammar and style in files like Markdown. It works by running a local LanguageTool server, keeping your data private. For a simpler, spell-check-focused approach, the 'Code Spell Checker' extension is another excellent offline-first tool that is adept at ignoring code and checking only the human-readable text in your comments and strings. These extensions transform your editor into a secure writing environment, ensuring your documentation and notes are as clean as your code.
Hack 4: Re-evaluate Built-in and Simpler Options
Don't overlook the tools you already have. The built-in spelling and grammar checkers in Microsoft Word and Google Docs have improved significantly. While Google Docs is a cloud product, for those already in its ecosystem, it processes data within that environment. For true offline work, Microsoft Word's editor remains a powerful option that functions without an internet connection. Furthermore, many modern browsers have built-in spell checkers that are smarter than they used to be, capable of catching repeated words or simple syntax errors without needing a third-party extension. While they lack the advanced stylistic suggestions of dedicated AI tools, they offer a baseline level of checking with zero privacy trade-offs.
