# GPTZero vs Lex

GPTZero records 23,246,989 monthly visits with +32.5% month-over-month growth and Freemium, Paid pricing. Lex records 24,323 monthly visits with -57.1% growth and Freemium pricing.

| Metric | [GPTZero](https://openaitools.app/tool/gptzero-me) | [Lex](https://openaitools.app/tool/lex) |
| :--- | :--- | :--- |
| Website URL | https://gptzero.me | https://lex.page |
| Categories | AI Detector, AI Checker, AI Content Detector, AI Plagiarism Checker | AI Writing, AI Writing Assistants, AI Copilot, AI Rewriter |
| Pricing Model | Freemium, Paid | Freemium |
| Monthly Visits | 23,246,989 | 24,323 |
| MoM Growth Rate | +32.5% | -57.1% |
| Primary Market | United States | United States |
| Direct Visits | 7,529,349 | 14,650 |
| Review Score | 4.1 | 1.8 |
| Saved Count | 41 | 0 |
| Supported Platforms | Website | Website |

## GPTZero

GPTZero grew out of the practical problem that teachers and editors faced once generative text became common: how do you tell whether a piece of writing came from a person or a model? The product answers that with a detector that returns an overall AI likelihood score and highlights individual sentences it considers machine-written, so a reader can see where the suspicion comes from rather than just receiving a single verdict.

Over time the platform widened from a single text box into a suite aimed at institutions. Detector results are paired with a plagiarism checker, grammar and writing feedback, and optional process verification such as a writing replay that records how a document was typed. A Chrome extension and Google Docs add-on push detection into the tools students and staff already use, and the company offers classroom integrations plus an API for bulk or programmatic checks.

Because the buyers are largely schools, districts, and universities, GPTZero leans heavily on privacy and compliance claims: it states SOC 2 Type II compliance and alignment with FERPA, GDPR, and CCPA, and says student writing is not used to train models. The practical takeaway is that it is positioned as an academic-integrity and editorial-review tool rather than a novelty checker, which also means its more powerful features sit in paid tiers.

**Pricing & Plans:** Freemium plus paid plans. A free tier provides core detection with character limits per scan, while paid individual and institutional plans unlock advanced scan modes, higher limits, writing reports, and classroom integrations. Enterprise and API access are quoted separately.

- **Sentence-level AI detection:** Paste text or upload a document and get an overall AI probability score plus a sentence-by-sentence breakdown of which parts look machine-written.
- **Multi-model coverage:** Flags AI text from major model families including ChatGPT, Gemini, Claude, Llama, and others, rather than training for a single model.
- **Browser and docs extensions:** A Chrome extension and Google Docs add-on bring scanning into Gmail, Docs, Classroom, and other surfaces you already work in.
- **Plagiarism checking:** Checks content for copied passages from outside sources so you can separate AI-generation questions from originality questions.
- **Writing process verification:** Writing replay and advanced reports offer evidence about how a document was produced, useful for academic integrity workflows.

**Strengths:** Sentence-level highlighting shows why a passage was flagged instead of only giving a score; Covers text from many different AI model families, not just one chatbot; Integrations with Chrome, Google Docs, Canvas, and Google Classroom fit existing school workflows; Publishes concrete compliance claims (SOC 2 Type II, FERPA, GDPR, CCPA) that institutions can review

**Limitations:** Detection is probabilistic and can flag polished human writing or miss lightly edited AI text; Free scans are capped by character count, and useful reporting features require payment; Lean heavily on a single score without human judgment can lead to unfair accusations

[Profile (Markdown)](https://openaitools.app/tool/gptzero-me.md)

## Lex

Lex is built around a simple premise: the editor should stay out of the way while the AI does useful work at the moment you need it. The interface is deliberately minimal and keyboard-driven, so you write in a distraction-free document rather than assembling blocks in a page builder. Sitting alongside the text is an AI layer that can critique your draft, brainstorm directions, rewrite a sentence or paragraph, and generate title ideas on demand.

For anything longer than a quick note, Lex behaves like a proper collaborative document tool. You can share a link so a collaborator logs in with a single click and types alongside you, leave comments navigated by keyboard shortcuts, and switch between versions to try a different phrasing without losing what you had. Publishing sends a read-only link for readers, and mobile web access means a shared link works without anyone installing an app.

One practical note for anyone evaluating it today: Lex currently displays a notice stating it is no longer accepting new customers, while existing accounts continue to work as usual. If you are already using Lex, the product is operational. If you are new, you may not be able to sign up right now.

**Pricing & Plans:** Lex has operated on a freemium model with free and paid tiers; the site currently states it is no longer accepting new customers, so new signups may not be available. Existing accounts keep working and pricing details remain published on the site.

- **AI feedback on your draft:** Ask the built-in assistant to critique a passage, brainstorm alternatives or rewrite something, without leaving the document.
- **One-click commands:** Keyboard-driven AI shortcuts find the better word, expand a bullet into prose or generate a list of ideas in place.
- **Comments and versions:** Threaded comments navigated by shortcut plus saved versions, so you can try a different way of saying something without losing the original.
- **Live collaboration and publishing:** Share a link for one-click co-editing in real time, or send a read-only link so others can simply read the finished piece.
- **Title generation:** Request a batch of title options from the AI and pick the strongest headline instead of agonising over the first line.

**Strengths:** Genuinely minimal, keyboard-first editor that stays out of the way of writing; AI assistance is embedded in the document rather than living in a separate chat window; Proper collaboration features: live co-editing, comments, versions and read-only publishing links; Works on mobile web through a shared link, so collaborators install nothing

**Limitations:** The site currently states Lex is no longer accepting new customers, so new users may be unable to sign up; Track changes was still listed as coming soon, so review workflows are less complete than a full office suite; AI features focus on wording and feedback rather than deep research or data analysis

[Profile (Markdown)](https://openaitools.app/tool/lex.md)

## Frequently Asked Questions

### How do GPTZero and Lex compare in monthly traffic?

GPTZero has 23,246,989 monthly visits, while Lex has 24,323. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

GPTZero has a month-over-month growth rate of +32.5%; Lex has -57.1%.

### How does pricing compare?

GPTZero: Freemium, Paid. Freemium plus paid plans. A free tier provides core detection with character limits per scan, while paid individual and institutional plans unlock advanced scan modes, higher limits, writing reports, and classroom integrations. Enterprise and API access are quoted separately. Lex: Freemium. Lex has operated on a freemium model with free and paid tiers; the site currently states it is no longer accepting new customers, so new signups may not be available. Existing accounts keep working and pricing details remain published on the site.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [QuillBot Paraphraser](https://openaitools.app/tool/quillbot-paraphraser) | 36,630,337 | +2.3% | Freemium | Paraphrase, proofread and summarize text with an AI writing workspace | [.md](https://openaitools.app/tool/quillbot-paraphraser.md) |
| 2 | [ZeroGPT](https://openaitools.app/tool/zerogpt) | 32,864,541 | +19.7% | Freemium, Paid | Offers broad multilingual AI detection and text humanization, but lacks GPTZero's detailed deep-scan reporting features. | [.md](https://openaitools.app/tool/zerogpt.md) |
| 3 | [Scribbr](https://openaitools.app/tool/scribbr) | 7,530,803 | +14.6% | Freemium | Combines AI detection with professional human proofreading and citation tools, but functions primarily as an editing service. | [.md](https://openaitools.app/tool/scribbr.md) |
| 4 | [Undetectable AI](https://openaitools.app/tool/undetectable-ai) | 3,113,403 | +17.5% | Freemium | Combines AI detection with robust text humanization tools, but focuses more heavily on rewriting than pure verification. | [.md](https://openaitools.app/tool/undetectable-ai.md) |
| 5 | [Copyleaks](https://openaitools.app/tool/copyleaks) | 2,402,494 | -14.1% | Paid, Contact for Pricing | Provides robust enterprise-grade content integrity and cross-media detection, but can be more expensive for individual users. | [.md](https://openaitools.app/tool/copyleaks.md) |
| 6 | [Originality.ai](https://openaitools.app/tool/originality) | 2,049,639 | +2.8% | Paid | Delivers strong fact-checking and comprehensive site-wide plagiarism audits, but has stricter paywalls than GPTZero. | [.md](https://openaitools.app/tool/originality.md) |
| 7 | [Jenni](https://openaitools.app/tool/jenni) | 1,498,133 | +5.2% | Freemium | The AI workspace where researchers read, write, and cite with every claim traceable to its source | [.md](https://openaitools.app/tool/jenni.md) |
| 8 | [Decopy AI](https://openaitools.app/tool/decopy-ai) | 1,256,528 | -11% | Free | One workspace to write, check and summarize | [.md](https://openaitools.app/tool/decopy-ai.md) |
| 9 | [Isgen AI Detector](https://openaitools.app/tool/isgen-ai) | 901,917 | +5.8% | Freemium | Provides detailed sentence-level analysis for multilingual text, but lacks GPTZero's broad academic brand recognition. | [.md](https://openaitools.app/tool/isgen-ai.md) |
| 10 | [Hemingway Editor](https://openaitools.app/tool/hemingway-editor) | 605,169 | -8.6% | Free Trial, Paid, Free | Write bolder, clearer prose with instant readability and grammar feedback | [.md](https://openaitools.app/tool/hemingway-editor.md) |

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Source: https://openaitools.app/compare/gptzero-me-vs-lex

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