AI paraphraser, grammar checker, summarizer and AI detector popular with students and writers.
Grammarly vs Koala AI
Features, pricing, strengths and trade-offs — and which one fits your situation.
The verdict
Summary
Grammarly is best for catching errors and polishing tone in everyday writing across the apps you already use, while Koala AI is best for generating SEO blog posts and Amazon affiliate roundups ready to publish. Only Grammarly offers grammar & style checking and works in browser / other apps. Grammarly has a free plan, while Koala AI offers a free trial.
Which should you choose?
Choose Grammarly if…
- You need catching errors and polishing tone in everyday writing across the apps you already use
- Grammar & style checking matters to you
- Works in browser / other apps matters to you
- You're one of: professionals writing emails and documents, students, non-native english writers
- You want a free plan (Koala AI only has a trial)
Choose Koala AI if…
- You need generating SEO blog posts and Amazon affiliate roundups ready to publish
- You're one of: niche and affiliate site owners, seo agencies, bloggers publishing at volume
- Produces structured, publish-ready articles quickly
At a glance
| Grammarly | Koala AI | |
|---|---|---|
| Best for | Catching errors and polishing tone in everyday writing across the apps you already use | Generating SEO blog posts and Amazon affiliate roundups ready to publish |
| Free plan | Yes | Trial only |
| Starting price | From $12/mo | From $25/mo |
| Learning curve | Low | Low |
| Platforms | Web, Windows, macOS, iOS, Android, Chrome extension | Web |
| Ideal for | Professionals writing emails and documents, Students, Non-native English writers, Business and support teams | Niche and affiliate site owners, SEO agencies, Bloggers publishing at volume |
Feature comparison
| Grammarly | Koala AI | |
|---|---|---|
| Grammar & style checking | Yes | No |
| Paraphrasing / rewriting | Paid plans only | — |
| Long-form drafting | Limited | Yes |
| Brand voice / style guide | Paid plans only | Yes |
| Plagiarism checker | Paid plans only | No |
| AI content detection | Paid plans only | No |
| Works in browser / other apps | Yes | No |
| Languages | English + 5 (translation 19) | Many languages |
| Team workspace | Yes | — |
IncludedLimited / higher plansNot available— Not confirmed
Security & enterprise
| Grammarly | Koala AI | |
|---|---|---|
| Business / enterprise plan | Yes | No |
| SSO (SAML / OIDC) | Enterprise plan | — |
| SCIM user provisioning | — | — |
| SOC 2 | Type II | — |
| ISO 27001 | Yes | — |
| HIPAA (BAA available) | Enterprise (BAA) | — |
| GDPR DPA | Yes | — |
| Data residency options | — | — |
| No training on your data | — | — |
| Audit logs | — | — |
| Admin controls | Yes | — |
| Deployment | Cloud | — |
From each vendor's security documentation. "—" = not confirmed. What to ask vendors · Compare all tools
What each tool does
Grammarly
Grammarly is an AI writing assistant that checks grammar, spelling, clarity and tone as you type in browsers, desktop apps, Microsoft Office, Google Docs and mobile keyboards. It also generates and rewrites text, and paid plans add plagiarism and AI-content detection, style guides and brand tones. Its parent company rebranded as Superhuman in 2025, but Grammarly continues as the writing assistant product.
Key features- Real-time grammar, spelling, clarity and tone suggestions
- Full-sentence rewrites and generative AI prompts
- Plagiarism and AI-content detection (paid)
- Style guides and brand tones for teams
- Grammar checks in five languages beyond English, translation into 19
- Works in browsers, desktop apps, Office, Google Docs and mobile
Koala AI
Koala AI (KoalaWriter) generates long-form, SEO-focused articles in one pass using real-time SERP analysis, then publishes them directly to WordPress, Shopify, Webflow or Ghost. It includes Amazon product roundups with live product data, automatic internal linking, a Brand DNA feature that learns your business, and KoalaChat, an assistant with live web data. It is used mainly by niche site owners, affiliate marketers and SEO agencies.
Key features- One-click long-form SEO articles with SERP analysis
- Amazon product roundups with live product data
- Brand DNA for brand voice and business details
- Automatic internal linking (KoalaLinks)
- One-click publishing to WordPress, Shopify, Webflow and Ghost
- KoalaChat with real-time web data
Pricing
Grammarly
Free plan. Pro ~$12/mo billed annually or ~$30 monthly. Enterprise custom.
Koala AI
Free trial (5,000 words + 25 credits, no card). Paid from $25/mo (Starter) up to $2,000/mo; 20% off annual.
Prices last checked September 2026. Plans change often — confirm on each vendor's site.
Pros and cons
Grammarly
Strengths- Works almost everywhere you type, including a mobile keyboard
- Clear, easy-to-accept suggestions with little setup
- Team features include style guides, snippets and analytics
- Has a useful free plan
- Rewrites, tone adjustment, plagiarism and AI detection require a paid plan
- Generative AI prompts are capped per month except on Enterprise
- Less depth for fiction and long manuscripts than specialist editors
- Full-sentence grammar support outside English covers only five languages
Not ideal for: Novelists wanting in-depth manuscript analysis, or marketers who need long-form content generated at scale, should look at specialist tools.
Koala AI
Strengths- Produces structured, publish-ready articles quickly
- Amazon roundup tool suits affiliate sites
- Direct publishing and internal linking save manual steps
- Writes in many languages
- No ongoing free plan, only a limited trial
- No built-in plagiarism checker or AI detector
- Not a grammar or editing assistant for your own writing
- Output still needs fact-checking and editing before publishing
Not ideal for: Writers who want help editing their own drafts, or brands producing short marketing copy, will get more from an editing assistant or copywriting tool.
Integrations
Grammarly
Koala AI
FAQ
What is the main difference between Grammarly and Koala AI?
Grammarly is built for catching errors and polishing tone in everyday writing across the apps you already use; Koala AI is built for generating SEO blog posts and Amazon affiliate roundups ready to publish. Key differences: Grammarly offers grammar & style checking and works in browser / other apps.
Is Grammarly or Koala AI cheaper?
Grammarly starts from $12/mo and Koala AI starts from $25/mo (as of September 2026). On entry price, Grammarly is cheaper — but compare what each plan includes, since limits differ. Always confirm current pricing on each vendor's site.
Do Grammarly and Koala AI have free plans?
Grammarly has a free plan, while Koala AI offers a free trial.
Which is easier to use, Grammarly or Koala AI?
Both have a low learning curve.
What are good alternatives to Grammarly and Koala AI?
Other writing tools worth comparing include QuillBot, Writesonic and Rytr.
