We may earn a commission if you buy through links on this page. It never changes a score or a ranking. How we make money
It's a split decision.
Choose GPTZero if your main job is checking whether text may be AI-generated; its free plan includes 10,000 words monthly, while paid plans offer higher limits. Choose Grammarly for proofreading, tone and clarity edits, and sentence rewrites. Its free plan includes 100 AI prompts monthly, and Pro is €12/month. GPTZero’s lowest paid rate is $12.99/month billed annually, so compare currencies and billing terms before switching.
01Side by side
| GPTZero | Grammarly | |
|---|---|---|
| Paid starting price | $12.99/month annual equivalent; $23.99 monthly | €12/month; billing cadence not specified |
| Free plan | 10,000 words/month; 1 advanced scan | 100 AI prompts/month; writing and tone features |
| Best for | Checking text for AI-generated content | Proofreading and improving everyday writing |
| Core strength | AI detection across major models | Grammar, tone, clarity and sentence rewrites |
| Learning curve | Not published | Not published |
| Integrations and listed controls | Canvas, Google Classroom; controls not published | Apps and text boxes; Enterprise DLP, BYOK encryption |
| Team / seat costs | Minimum 2 seats; $24.99 annual or $45.99 monthly | Enterprise pricing custom; team seat price not published |
| Support | Support details not published | Support details not published |
GPTZero Choose GPTZero if
- Choose GPTZero if AI-text detection is your main need.
- Choose GPTZero if you need Canvas or Google Classroom integrations.
- Choose GPTZero if you want published team seat pricing.
Grammarly Choose Grammarly if
- Choose Grammarly if proofreading and tone edits are your priority.
- Choose Grammarly if you want full-sentence rewrites.
- Choose Grammarly if Enterprise DLP and BYOK encryption matter.
02Pricing compared
GPTZero’s free plan includes 10,000 words per month, with a 10,000-character scan limit and one advanced scan. Its lowest paid rate is Premium at $12.99 per month when billed annually; monthly billing is $23.99. Professional costs $24.99 per month annually or $45.99 monthly. The team plan has the same listed rates per seat and requires at least two seats.
Grammarly offers a free plan with 100 AI prompts per month. Pro is listed at €12 per month and includes 2,000 prompts per member, rewrites, plagiarism checking, and AI-text detection. Grammarly also offers a free Pro trial. These prices are in different currencies and use different billing terms, so the headline rates are not a direct comparison.
03Features and depth
GPTZero is built around detecting text that may come from AI models including ChatGPT, Claude, Gemini, and Llama. Its homepage claims 99.9% accuracy, but a detector score should be treated as a signal, not proof. The product also lists plagiarism checking, writing feedback, a Writing Replay video showing how a Google Doc was typed, and Canvas and Google Classroom integrations. Advanced Scan is presented as a higher-accuracy tier.
Grammarly’s core job is editing: it checks grammar, tone, clarity, and style in text fields, including apps such as Zendesk. Its homepage lists paragraph rewrites and a humanizer agent; Pro adds full-sentence rewrites, tone adjustment, plagiarism checking, and an AI-text detection agent. Pro also includes a style guide and brand tone settings. Choose GPTZero for a detection-focused workflow; choose Grammarly when the main need is revising writing, with detection as an additional feature.
04Ease of use and learning curve
The simpler fit depends on the task. GPTZero’s workflow centers on scanning text or files and reviewing detection results; its free plan caps scans at 10,000 characters each, so longer documents may require a paid plan. Teams should also account for the two-seat minimum and shared credits.
Grammarly works inside text boxes in apps such as Zendesk, so its editing suggestions can sit alongside the writing task. Its free plan covers proofreading and tone, while Pro adds more prompts and rewrite tools. For a switch, compare where your team writes and whether you need detection results or ongoing editing. The published plan details do not specify setup time or training requirements for either product.
Questions people ask
Is Grammarly considered AI?
Yes. Grammarly describes itself as an AI-powered writing assistant and offers AI prompts, rewrites, a humanizer agent, and an AI-text detection agent. Its editing features also cover grammar, tone, and clarity, so it is not only an AI text generator.
What is GPTZero?
GPTZero is an AI-content detector that scans text for possible output from models such as ChatGPT, Claude, Gemini, and Llama. It also offers plagiarism checking, writing feedback, document replay, and classroom integrations. Its detection results are signals, not conclusive proof of authorship.
Is Grammarly Pro $12 a month?
The published pricing lists Grammarly Pro at €12 per month, not $12. It includes 2,000 AI prompts per member per month, full-sentence rewrites, tone adjustment, plagiarism checking, AI-text detection, and style-guide features. Check the pricing page for current currency and terms.
Is this ChatGPT?
If you mean a passage you have written, GPTZero can scan it for signs of AI-generated text, but a result cannot prove that ChatGPT wrote it. Grammarly also lists an AI Detector agent. Neither product description makes a detector result definitive evidence of authorship.