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Merlin AI vs StealthGPT
Features, pricing, strengths and trade-offs — and which one fits your situation.
The verdict
Summary
Merlin AI is best for using multiple AI models on any web page through a browser extension, while StealthGPT is best for rewriting AI-generated drafts so they read less like machine text. Merlin AI has a free plan, while StealthGPT has no free plan.
Which should you choose?
Choose Merlin AI if…
- You need using multiple AI models on any web page through a browser extension
- You're one of: knowledge workers who live in the browser, students summarizing videos and articles, professionals drafting emails and linkedin posts
- You want a free plan (StealthGPT doesn't have one)
- One subscription covers several providers' models
Choose StealthGPT if…
- You need rewriting AI-generated drafts so they read less like machine text
- You're one of: content writers editing ai-assisted drafts where ai use is permitted, marketers adjusting tone of ai copy
- Simple paste-and-rewrite workflow
At a glance
| Merlin AI | StealthGPT | |
|---|---|---|
| Best for | Using multiple AI models on any web page through a browser extension | Rewriting AI-generated drafts so they read less like machine text |
| Free plan | Yes | Check site |
| Starting price | From $19/mo | From $14.99/mo |
| Learning curve | Low | Low |
| Platforms | Web, iOS, Android, Chrome extension | Web, Chrome extension |
| Ideal for | Knowledge workers who live in the browser, Students summarizing videos and articles, Professionals drafting emails and LinkedIn posts | Content writers editing AI-assisted drafts where AI use is permitted, Marketers adjusting tone of AI copy |
Feature comparison
| Merlin AI | StealthGPT | |
|---|---|---|
| Answers with citations | Yes | Limited |
| Searches academic papers | — | No |
| Upload & chat with PDFs | Yes | — |
| AI content detection | Yes | Yes |
| Rewrites / humanizes text | Yes | Yes |
| Citation formatting | — | — |
| Browser extension | Yes | Yes |
| Writing editor | — | Limited |
IncludedLimited / higher plansNot available— Not confirmed
Security & enterprise
| Merlin AI | StealthGPT | |
|---|---|---|
| Business / enterprise plan | Yes | No |
| SSO (SAML / OIDC) | Enterprise plan | — |
| SCIM user provisioning | Enterprise plan | — |
| SOC 2 | Type II | — |
| ISO 27001 | Yes | — |
| HIPAA (BAA available) | — | — |
| GDPR DPA | Enterprise plan | — |
| Data residency options | — | — |
| No training on your data | Yes | — |
| Audit logs | — | — |
| Admin controls | Yes | — |
| Deployment | Cloud | — |
From each vendor's security documentation. "—" = not confirmed. What to ask vendors · Compare all tools
What each tool does
Merlin AI
Merlin AI is a browser extension and web app that gives access to many AI models (from OpenAI, Anthropic, Google and others) in one place. It summarizes web pages and YouTube videos, helps write emails and posts inside Gmail and LinkedIn, and chats with uploaded files. It also bundles tools such as an AI detector and humanizer.
Key features- Chrome extension that opens an AI sidebar on any page
- Access to multiple models from different providers
- YouTube and web page summaries
- Gmail and LinkedIn writing assistance
- Chat with PDFs and other uploaded files
- AI detector and AI humanizer tools
StealthGPT
StealthGPT is an AI writing tool that combines a text generator with a 'humanizer' that rewrites AI text to lower AI-detector scores, plus a free AI detector. It is marketed mainly to students and content writers. Using it to submit AI-written work as your own can breach academic integrity and client policies.
Key features- AI humanizer that rewrites existing AI text
- Stealth Writer for generating essays and articles
- Built-in AI detector
- Adjustable rewrite tone and strength
- Chrome extension for rewriting in place (higher tiers)
Pricing
Merlin AI
Free plan; Pro ~$19/mo, cheaper annually
StealthGPT
Paid from ~$14.99/mo; ~30% off annual
Prices last checked September 2026. Plans change often — confirm on each vendor's site.
Pros and cons
Merlin AI
Strengths- One subscription covers several providers' models
- Works inside the sites you already use
- Free plan with daily queries
- Also available on iOS and Android
- Top models are limited or reduced on the free plan
- Query-based limits can run out quickly with premium models
- Browser extension requires broad page access permissions
- Not a dedicated academic research tool; no specialized paper database
Not ideal for: Researchers who need rigorous academic sourcing should use Consensus, Elicit or Scite instead.
StealthGPT
Strengths- Simple paste-and-rewrite workflow
- AI detector can be used without signing up
- Combines generation and rewriting in one tool
- Tone controls help match a target style
- No permanent free plan for the humanizer
- Independent tests show mixed results against current detectors
- Rewrites can introduce awkward phrasing or change meaning
- Using it to disguise AI work can violate school and employer policies, with serious consequences
Not ideal for: Students whose institutions prohibit undisclosed AI use should not use it for graded work; a research or citation tool is a better fit for legitimate study.
Integrations
Merlin AI
StealthGPT
FAQ
What is the main difference between Merlin AI and StealthGPT?
Merlin AI is built for using multiple AI models on any web page through a browser extension; StealthGPT is built for rewriting AI-generated drafts so they read less like machine text.
Is Merlin AI or StealthGPT cheaper?
Merlin AI starts from $19/mo and StealthGPT starts from $14.99/mo (as of September 2026). On entry price, StealthGPT is cheaper — but compare what each plan includes, since limits differ. Always confirm current pricing on each vendor's site.
Do Merlin AI and StealthGPT have free plans?
Merlin AI has a free plan, while StealthGPT has no free plan.
Which is easier to use, Merlin AI or StealthGPT?
Both have a low learning curve.
What are good alternatives to Merlin AI and StealthGPT?
Other research & study tools worth comparing include Perplexity, Consensus and Monica.
