GrammarlyFreemium
AI writing assistant for grammar, clarity, tone, and generative drafts across every app you write in.
AI / LLM comparison
Grammarly vs OpenAI API
Pricing, pros, cons, and ideal use cases — side by side.
OpenAI APIPaid
The most capable AI models available via API — power your business automations with GPT-4.
At a glance
| Grammarly | OpenAI API | |
|---|---|---|
| Pricing | FreemiumFree plan available. Premium $12/month. Business from $15/seat/month. | PaidPay-as-you-go. GPT-4o roughly $5/1M input tokens. Very affordable for SMB usage volumes. |
| Category | AI / LLM | AI / LLM |
| Ideal for | Any SMBLaw FirmsAgenciesCustomer Support TeamsProfessional Services | Any SMB wanting AI featuresLaw FirmsRecruitersAgencies |
Pros & cons
Grammarly
Pros
- Works in every major app
- Strong brand voice features
- Tone detection is excellent
- Good generative AI drafts
Cons
- Browser extension can slow pages
- Plagiarism check is weaker than dedicated tools
- Advanced suggestions need premium
OpenAI API
Pros
- Most capable models available
- Flexible API
- Good documentation
Cons
- Requires technical setup
- Costs can grow with volume
- Outputs need review
Which should you choose?
Grammarly is the lighter-weight option (Freemium), while OpenAI API sits higher on the pricing ladder (Paid). Grammarly is built around any smb; OpenAI API leans more toward any smb wanting ai features. Shortlist the one whose strengths line up with your biggest constraint.