Grammarly

Grammarly's core strength is precision at the sentence level — it catches the kind of errors spell-check misses entirely: subject-verb agreement across long sentences, misused prepositions, and awkward phrasing that's grammatically valid but reads poorly. We ran it against a technical report with dense, jargon-heavy sentences, and its suggestions consistently improved clarity without flattening the writer's voice into generic corporate tone, which is a real risk with more aggressive AI rewriting tools.

The 'Tone Detector' is genuinely useful in a way that's easy to underestimate: it flags when an email or message might read as more blunt, demanding, or informal than intended before you send it — catching a real communication problem, not just a grammar one. The browser extension and near-universal integration (Gmail, Slack, Google Docs, most text fields across the web) means it works passively in the background across your actual writing, rather than requiring you to paste text into a separate tool.

The generative AI features (added more recently to compete with GPT-based writing tools) are solid for short rewrites and tone adjustments but are noticeably weaker than a dedicated chatbot for longer-form content generation from scratch — Grammarly's core competency is still editing and refining existing text, not generating long original pieces. Free tier suggestions are also fairly basic; the more nuanced clarity and tone suggestions sit behind Grammarly Premium. For catching real errors and communication issues across everyday writing (email, docs, Slack), Grammarly remains genuinely reliable; for generating long-form content from a blank page, a dedicated writing assistant or chatbot is the better tool.