All industries · head to head
Slack vs Grammarly
The short version
- Each has a real cost: Slack 90-day message history limit on free plan results in important conversations disappearing; Grammarly occasional false positives and grammatically incorrect suggestions that can introduce errors
- They diverge on capability: Slack covers Channels, Grammarly covers Grammar checking.
Where they differ
Only the attributes on which Slack and Grammarly actually diverge.
Identical on both: starting price (Free), pricing model (Unknown), free tier (Yes), user rating (Not yet rated), category (All industries), founded (2009).
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 Slack
- Channels
- Direct messaging
- Voice & video calls
- Screen sharing
- File sharing
- Search
- Workflow builder
- Slack Connect
Only in Grammarly
- Grammar checking
- Spelling correction
- Punctuation
- Clarity suggestions
- Engagement feedback
- Delivery insights
- Plagiarism checker
- Citation generator
Both cover
- SOC2
What people use each for
The jobs each tool is most often brought in to do.
Slack
- Team communicationnot Grammarly
- Project coordinationnot Grammarly
- Customer supportnot Grammarly
- Remote worknot Grammarly
- Cross-functional collaborationnot Grammarly
Grammarly
- Email writingnot Slack
- Document editingnot Slack
- Academic writingnot Slack
- Business communicationnot Slack
- Content creationnot Slack
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Slack
- 90-day message history limit on free plan results in important conversations disappearing
- Per-user pricing becomes expensive quickly for larger teams
- Notification overload with 78% of employees feeling overwhelmed by notifications
- Mobile app performance issues including lag and slow syncing
- Huddles limited to 50 people and cannot be recorded
- Requires dedicated video conferencing service for formal meetings and webinars
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
Pricing, plan by plan
Slack
FreeNo published plan breakdown. See the Slack review.
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
Which should you pick?
Choose Slack if
- You need channels.
- You want to start without paying.
- You work on Web, iOS, Android, macOS, Windows, Linux.
- You also want direct messaging.
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.
Questions people ask
- Is Slack or Grammarly better?
- Neither clearly leads. Slack starts at Free and Grammarly at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Slack or Grammarly?
- Slack starts at Free and Grammarly at Free.
- Does Slack or Grammarly run on more platforms?
- Slack runs on Web, iOS, Android, macOS, Windows, Linux. Grammarly runs on Web, macOS, Windows, iOS, Android.
- Can I use Slack for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Slack best used for?
- Slack is most often used for team communication, project coordination, customer support, remote work. Of those, team communication and project coordination are not what Grammarly is typically brought in for.
- What can Slack do that Grammarly cannot?
- Slack covers Channels, Direct messaging, Voice & video calls, Screen sharing. Grammarly covers Grammar checking, Spelling correction, Punctuation, Clarity suggestions. Both handle SOC2.
Answered from the vendors’ own pages
Slack: Does Slack have a free plan?
Yes, Slack offers a free plan indefinitely with no credit card required. Free users get 90-day message history, up to 10 app integrations, and 1:1 huddles.
SourceGrammarly: 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.
SourceSlack: What are Slack's pricing plans?
Slack offers Free, Pro ($7.25/user/month with annual billing), Business+ ($12.50/user/month), and Enterprise Grid (custom pricing). Monthly billing costs approximately 20% more than annual.
SourceGrammarly: 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.
SourceSlack: Does Slack support offline use?
Slack is a cloud-based platform and does not support robust offline work. Internet connectivity is required to access messages and collaborate.
SourceGrammarly: 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.
SourceSlack: What integrations does Slack support?
Slack integrates with 43+ apps on average per team, including Google Drive, ChatGPT, Vercel, Asana, GitHub, and many others through their app marketplace.
SourceGrammarly: 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