Grammarly vs Mainframe
Which Agents AI tool is better in 2026?
Grammarly
AI writing assistant for individuals and teams.
Mainframe
Building interfaces for the future where operating systems are built around actions, not apps, powered by AI.
Side-by-side
| Grammarly | Mainframe | |
|---|---|---|
| Tagline | AI writing assistant for individuals and teams. | Building interfaces for the future where operating systems are built around actions, not apps, powered by AI. |
| Founded | 2009 | 2026 |
| 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 | Enterprise · Contact sales |
| Categories |
Capability matrix
Developer-facing capabilities and access signals for Grammarly and Mainframe.
| Capability | Grammarly | Mainframe |
|---|---|---|
| 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 28)
- Offers a free plan
- Offers a free trial
🔵 Strengths of Mainframe
- Newer company (2026)
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 Mainframe — which is better?
It depends on your priority. Grammarly has raised more capital and is the more established option; Mainframe has broader feature depth. See the side-by-side table above.
Is Grammarly cheaper than Mainframe?
Yes — Grammarly's cheapest paid plan is Pro (Annual) · $12/mo, while Mainframe's is Enterprise · Contact sales.
Do Grammarly and Mainframe offer free plans?
Grammarly: Yes, has a free plan. Mainframe: Paid only.
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