Grammarly vs Ninja AI
Which Agents AI tool is better in 2026?
Grammarly
AI writing assistant for individuals and teams.
Ninja AI
Your all-in-one AI agent for boundless productivity, automating tasks and streamlining workflows across your digital life.
Side-by-side
| Grammarly | Ninja AI | |
|---|---|---|
| Tagline | AI writing assistant for individuals and teams. | Your all-in-one AI agent for boundless productivity, automating tasks and streamlining workflows across your digital life. |
| Founded | 2009 | — |
| HQ | San Francisco, US | — |
| Employees | 1001-5000 | 1-10 |
| Total funding | $200M | Undisclosed |
| Latest round | Series D · Nov 2024 | — |
| Valuation | $13B | — |
| Cheapest paid plan | Pro (Annual) · $12/mo | Pricing not disclosed |
| Free plan | ✓ Free | ✓ |
| Free trial | ✓ | ✓ |
| Top tier price | Pro (Monthly) · $30/mo | Pricing not disclosed |
| Pricing summary | 6 published plans | Free |
| Categories |
Capability matrix
Developer-facing capabilities and access signals for Grammarly and Ninja AI.
| Capability | Grammarly | Ninja AI |
|---|---|---|
| MCP support | ✗ | ✗ |
| Public API | ✗ | ✗ |
| Webhooks | ✗ | ✗ |
| OAuth 2.0 | ✗ | ✗ |
| SDK languages | 1 (JavaScript) | — |
| Free plan | ✓ | ✓ |
| Free trial | ✓ | ✓ |
| Verified | ✗ | ✗ |
| Active deal | ✓ | ✗ |
🟢 Strengths of Grammarly
- Has raised more capital ($200M vs Undisclosed)
- Higher Neuron score (64 vs 15)
- Lower starting price ($12/mo)
- Newer company (2009)
🔵 Strengths of Ninja AI
- Strong in AI Agents
Which should you choose?
Choose Grammarly if price matters most — it starts at Free · From $12/mo, which is friendlier for teams watching burn. Both AI Agents tools ship core features, so the cost delta often decides it for small teams and solo operators.
Choose Grammarly if you want the most established option — it has raised $200M, suggesting more runway for enterprise features, support, and long-term roadmap. For mission-critical workflows or larger teams, that stability often outweighs a lower monthly price.
💸 Deals
7-day free trial of Grammarly Premium
Try Grammarly Premium free for 7 days — AI writing assistant used by 30M+ daily.
Frequently asked questions
Grammarly vs Ninja AI — which is better?
It depends on your priority. Grammarly has raised more capital and is the more established option; Ninja AI has broader feature depth. See the side-by-side table above.
Is Grammarly cheaper than Ninja AI?
Yes — Grammarly's cheapest paid plan is Pro (Annual) · $12/mo, while Ninja AI's is Free.
Do Grammarly and Ninja AI offer free plans?
Grammarly: Yes, has a free plan. Ninja AI: Yes, has a free plan.
Explore more AI Agents tools
Contextual paths to related AI startups, deals and rankings.