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Documentation · head to head

Grammarly vs Mercury Reader

Grammarly logo

Grammarly

Documentation

Great writing, simplified

From
Free
Rated
-
Full reviewWebsite
M

Mercury Reader

Browser Extensions

Clear clutter from articles instantly

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Grammarly occasional false positives and grammatically incorrect suggestions that can introduce errors; Mercury Reader mercury Reader's underlying engine (Postlight Parser) is free open source software licensed under Apache License 2.0, per the GitHub repository, with no paid tier
  • They diverge on capability: Grammarly covers Grammar checking, Mercury Reader covers Content extraction.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Grammarly and Mercury Reader actually diverge.

Attributes where Grammarly and Mercury Reader differ
AttributeGrammarlyMercury Reader
Pricing modelUnknownfree
PlatformsWeb, macOS, Windows, iOS, AndroidChrome, Firefox, Edge
CategoryDocumentationBrowser Extensions
Founded20092015

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Grammarly

  • Grammar checking
  • Spelling correction
  • Punctuation
  • Clarity suggestions
  • Engagement feedback
  • Delivery insights
  • Plagiarism checker
  • Citation generator

Only in Mercury Reader

  • Content extraction
  • Clean reading view
  • Custom themes
  • Font customization
  • Chrome support
  • Firefox support
  • Edge support

What people use each for

The jobs each tool is most often brought in to do.

Grammarly

  • Email writingnot Mercury Reader
  • Document editingnot Mercury Reader
  • Academic writingnot Mercury Reader
  • Business communicationnot Mercury Reader
  • Content creationnot Mercury Reader

Mercury Reader

No use cases recorded yet. See the Mercury Reader review.

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Grammarly

  • Occasional false positives and grammatically incorrect suggestions that can introduce errors
  • Privacy concerns about sending text to Grammarly's servers for analysis
  • AI capabilities sometimes produce hallucinations and fabricated citations that appear grammatically correct

Mercury Reader

  • Mercury Reader's underlying engine (Postlight Parser) is free open source software licensed under Apache License 2.0, per the GitHub repository, with no paid tier

Pricing, plan by plan

Grammarly

Free
  • FreeFree
    • Basic grammar and spelling checks
    • Tone visibility
    • 100 AI prompts per month
  • Pro$12/month
    • Sentence rewrites
    • Tone adjustment
    • Plagiarism and AI detection

Mercury Reader

Free
  • FreeFree
    • Clutter removal
    • Clean reading
    • Custom themes

Which should you pick?

Choose Grammarly if

  • You need grammar checking.
  • You want to start without paying.
  • You work on Web, macOS, Windows, iOS, Android.
  • You also want spelling correction.
Grammarly review

Choose Mercury Reader if

  • You need content extraction.
  • You want to start without paying.
  • You work on Chrome, Firefox, Edge.
  • You also want clean reading view.
Mercury Reader review

Questions people ask

Is Grammarly or Mercury Reader better?
Neither clearly leads. Grammarly starts at Free and Mercury Reader at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Grammarly or Mercury Reader?
Grammarly starts at Free and Mercury Reader at Free.
Does Grammarly or Mercury Reader run on more platforms?
Grammarly runs on Web, macOS, Windows, iOS, Android. Mercury Reader runs on Chrome, Firefox, Edge.
Can I use Grammarly for free?
Both have a free tier, so you can try either at no cost before committing.
What is Grammarly best used for?
Grammarly is most often used for email writing, document editing, academic writing, business communication. Of those, email writing and document editing are not what Mercury Reader is typically brought in for.
What can Grammarly do that Mercury Reader cannot?
Grammarly covers Grammar checking, Spelling correction, Punctuation, Clarity suggestions. Mercury Reader covers Content extraction, Clean reading view, Custom themes, Font customization.

Answered from the vendors’ own pages

Grammarly: Does Grammarly have a free version?

Yes, Grammarly offers a free tier with basic spelling, grammar, and punctuation checks, tone visibility, and 100 AI prompts per month. The Pro plan ($12/month annual) adds sentence rewriting, plagiarism detection, and 2,000 AI prompts.

Source
Grammarly: What platforms does Grammarly work with?

Grammarly works across 1 million+ apps including Google Docs, Microsoft Word, Outlook, Slack, Gmail, and web browsers. It also integrates with productivity tools like Asana, Jira, Monday.com, Confluence, and HubSpot.

Source
Grammarly: Can I use Grammarly offline?

Grammarly requires an internet connection to function, though the browser extension works with some offline text areas. For offline use, the desktop app and browser extensions sync when reconnected.

Source
Grammarly: What is included in the Enterprise plan?

The Enterprise plan includes unlimited team members, dedicated support, custom roles and permissions, data loss prevention, bring-your-own-key encryption, and unlimited AI prompts. Pricing is custom and available by contacting sales.

Source
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