Near-universal grammar and writing assistant, rebranded to Superhuman (Oct 2025). Acquired Coda and Superhuman Mail. Brand tone claims 40% improvement. Pivoting from pure writing to AI productivity suite.
Where it wins
Near-universal adoption in English-speaking markets
Brand tone claims 40% improvement for enterprise teams
Acquired Superhuman (email) and Coda (workspace) — expanding to AI productivity suite
Free tier + Premium from $12/mo — accessible pricing
Where to be skeptical
HN community deeply skeptical — privacy/keylogger concerns (645pts for Harper alternative, 464pts negative coverage)
Lighter governance than Writer.com for enterprise content governance
Rebrand dilutes writing-tool identity — pivoting to general AI assistant
Proprietary, closed-source
Editorial verdict
Best for broad writing assistance at enterprise scale. Near-universal adoption. Rebrand to Superhuman signals pivot away from pure writing toward AI productivity suite. HN community deeply skeptical (privacy/keylogger concerns, 464pts negative). Lighter governance than Writer.com.
Related
Harper
85Open-source, privacy-first grammar checker built in Rust + WebAssembly. Sub-10ms on-device processing. Browser extensions (Chrome, Firefox), editor plugins (VS Code, Neovim, Obsidian, WordPress). Backed by Automattic. Apache 2.0.
LanguageTool
84Open-source multilingual grammar and style checker supporting 30+ languages. Self-hostable, SOC 2 compliant, GDPR-friendly. Free tier + Premium from $4.99/mo. Written in Java. 14,184 GitHub stars — highest in content-writing category.
Vale
80Open-source prose linter for docs-as-code pipelines. Markup-aware (Markdown, reStructuredText, AsciiDoc, HTML), CI/CD-native, extensible style packages (Microsoft, Google, write-good). Written in Go.
proselint
72Prose linter based on advice from world-class writers and editors. 4,519 GitHub stars but 247 open issues signals maintenance debt. Vale has a proselint-compatible package.
Public evidence
Grammarly changed its company name to Superhuman, uniting Grammarly, Coda, and Superhuman Mail under one brand. No longer just a writing tool — becoming an AI productivity suite.
Enterprise teams using brand tones saw communication become on average 40% more on-brand. Quantified ROI for enterprise content governance.
Thread demonstrates strong demand for privacy-first, open-source alternatives to Grammarly. Developer/technical audience distrusts Grammarly — creates opportunity for Harper, LanguageTool, Vale.
Raw GitHub source
GitHub README could not be fetched right now.