Grammarly AI vs Jasper
Text Generation
| G Grammarly AI | J Jasper | |
|---|---|---|
| Free tier | ✓ Free tier | Paid only |
| Pricing model | subscription | subscription |
| Price | $12 (Pro) | $69 (Pro) |
| Features | ||
| Languages | en | en |
| API | ✓ Available Docs ↗ | ✓ Available Docs ↗ |
| Homepage | Grammarly AI ↗ | Jasper ↗ |
| Pricing Plans | Free$0/月文法・スペルチェック、トーン検出、AIプロンプト100回 Pro$12/月書き換え、明瞭さの提案、生成AI Enterprise要問合せスタイルガイド、管理機能 | Pro$69/月年払は月$59。Brand Voice 2つ Business要問合せAPI、Brand Voice 無制限、SSO |
| Platforms | ||
| Integrations | Chrome extension, Microsoft Word, Google Docs, Outlook, Slack, VS Code, Grammarly API, Figma | Surfer SEO, Grammarly, Google Docs, Chrome extension, Zapier, HubSpot, Salesforce, Jasper API |
- Best-in-class grammar, spelling, and style correction
- Browser extension works across virtually every web-based writing surface
- Tone adjustment and clarity rewrites improve communication quality
- Business plan includes style guides for brand consistency
- Generative AI features are weaker than dedicated tools like ChatGPT
- It is built around English; it is not the tool to pick for proofreading Japanese.
- Privacy concerns as all text passes through Grammarly servers
- Brand Voice feature ensures consistent tone across all content
- 50+ pre-built templates cover every marketing content type
- Integrates with Surfer SEO for optimized article creation
- Multi-language support across 30+ languages
- There is no free plan, only a 7-day trial, and the entry plan is $69/month — expensive for the category.
- Output quality is comparable to ChatGPT but at a higher price
- The API is Business-only, so the Pro plan cannot be built into an automated pipeline.
Our Verdict
- The goal is improving prose you wrote yourself — grammar, style and clarity are the core of the product.
- You do not want to change where you write. The browser extension works in Gmail, Slack, docs and almost any text field.
- The free plan already covers grammar checking and 100 AI prompts a month, and Pro is only $12/month.
- You need drafts from nothing. Grammarly can generate, but it is weaker than a dedicated tool.
- You want an organisational tone registered in Brand Voice and applied across several writers.
- You write in languages other than English; Grammarly is built around English.
Overview
Grammarly has evolved from a grammar checker into a full AI writing assistant, but its core strength remains its deeply trained understanding of English grammar, style, and clarity. The browser extension's ubiquity — working in Gmail, Slack, Google Docs, and virtually any text field in Chrome — makes it uniquely integrated into daily writing workflows without requiring any context switching. The Business tier's style guide feature allows organizations to enforce specific terminology and writing conventions automatically. However, its generative AI capabilities are relatively basic, and its English-only scope limits international adoption.
Jasper is positioned as the enterprise-grade AI writing assistant, competing less on raw model capability and more on workflow features designed for marketing teams. Its Brand Voice technology allows organizations to encode their tone, style guidelines, and product knowledge so every piece of AI-generated content stays on-brand. The tight integration with Surfer SEO makes it a strong choice for content teams focused on organic search performance. However, the pricing is significantly higher than alternatives, and the underlying language model quality is not demonstrably superior to what's available in ChatGPT or Claude.
