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Grammarly

API

Catch grammar and clarity issues as you write, then let built-in AI agents draft, rewrite, and complete tasks across your apps. Grammarly's parent company rebranded to Superhuman in October 2025.

Writing
4.7freemium

Best For

Catching grammar and clarity issues in real time as you write anywhere online

Standout Feature

Built-in AI agents now draft and rewrite across your apps, not just proofread

Verdict

The baseline writing check most people should already have running.

Alternatives

Overview

Grammarly is a widely deployed AI writing assistant for real-time clarity and correctness improvements, active across email clients, browsers, document editors, and development environments through browser extensions and native integrations. Its core product has evolved well beyond spell-check: the AI analyzes writing for clarity, conciseness, tone, engagement, and delivery effectiveness, offering specific rewrites rather than vague suggestions. The Tone Detector identifies how a piece is likely to land with readers, formal, friendly, apologetic, confident, enabling intentional adjustments before sending.

Grammarly Business adds a centralized Style Guide that enforces organization-specific vocabulary, banned phrases, and formatting rules across all team communications, ensuring consistency at scale. The premium tier ($12/month) adds the full suite of tone, clarity, and engagement suggestions beyond basic grammar correction. For professionals who write extensively, client-facing emails, reports, proposals, support communications, Grammarly's browser-level integration means these improvements apply everywhere you write without changing your workflow.

Its primary limitation is that it excels at polishing existing writing rather than generating new content, which keeps it complementary to rather than competitive with generation-focused AI tools.

Key Features

  • Grammar and spelling checks
  • Tone detection
  • Plagiarism checker
  • Generative AI co-creator
  • Browser extension
Pros
  • Works everywhere you write
  • Highly accurate suggestions
  • Improves overall writing quality
  • Generative features are helpful
Cons
  • Premium plan is somewhat pricey
  • Can be overly pedantic
  • Generative features are basic compared to ChatGPT

Other Writing tools builders reach for alongside Grammarly.