# Grammarly vs Inbox Zero

Grammarly records 58,867,412 monthly visits with -1.5% month-over-month growth and Freemium pricing. Inbox Zero records 89,348 monthly visits with +6.8% growth and Freemium, Free Trial pricing.

| Metric | [Grammarly](https://openaitools.app/tool/grammarly) | [Inbox Zero](https://openaitools.app/tool/inbox-zero) |
| :--- | :--- | :--- |
| Website URL | https://www.grammarly.com | https://www.getinboxzero.com |
| Categories | AI Writing Assistants, AI Writing, AI Grammar Checker, AI Text Generator | AI Email Assistant, AI Assistant, AI Productivity Tools, AI Email Writer |
| Pricing Model | Freemium | Freemium, Free Trial |
| Monthly Visits | 58,867,412 | 89,348 |
| MoM Growth Rate | -1.5% | +6.8% |
| Primary Market | United States | United States |
| Direct Visits | 25,398,749 | 26,075 |
| Review Score | 4.4 | 4.4 |
| Saved Count | 74 | 6 |
| Supported Platforms | Website | Website |

## Grammarly

Grammarly is the world's most widely deployed AI writing and communication platform, trusted by more than 40 million daily users and 50,000 organizations including Atlassian, Databricks, and Zoom. Operating as a persistent overlay across over 500,000 web applications, desktop programs (Windows and macOS), Microsoft Office, Google Docs, and iOS/Android keyboards, Grammarly analyzes text in real time to eliminate grammatical errors, streamline wordy phrasing, and calibrate tone to match the writer's intent. Following its corporate evolution under the Superhuman Platform umbrella alongside Superhuman Mail and Coda, Grammarly has expanded from a personal proofreader into an enterprise-grade proactive AI communication suite.

In 2026, Grammarly goes well beyond red-underline spellchecking with a suite of specialized AI Agents and document integrity tools. Writers can invoke purpose-built agents—including AI Grader, Citation Finder, Reader Reactions, and Paraphraser—alongside generative AI drafting directly inline where they work. To address academic and professional transparency in the generative AI era, Grammarly offers built-in Plagiarism Detection, an AI Detector, and Grammarly Authorship, which tracks how a document was constructed by automatically categorizing text as human-typed, pasted from external sources, or generated/modified with AI. For teams, Grammarly enforces organizational consistency through custom Style Guides, Brand Tones, reusable Snippets, and Knowledge Share.

Grammarly simplified its subscription structure by consolidating its legacy individual 'Premium' and team 'Business' offerings into a single unified tier: Grammarly Pro. The Free plan ($0/month) covers essential spelling, punctuation, basic tone visibility, and 100 generative AI prompts per month. Grammarly Pro is priced at $12/member/month when billed annually ($144/year) or $30/member/month when billed monthly ($60 quarterly), unlocking unlimited personalized fluency suggestions, full-sentence rewrites, tone adjustment, citation formatting, plagiarism and AI detection, 1 team style guide, and 2,000 generative AI prompts per member each month. Large organizations opt for Grammarly Enterprise (available with Superhuman Go) for unlimited AI prompts, SAML SSO, SCIM provisioning, Data Loss Prevention (DLP), and Bring Your Own Key (BYOK) encryption.

**Pricing & Plans:** Free plan ($0/month) includes core grammar and spelling checks, tone detection, and 100 generative AI prompts/month; Grammarly Pro costs $12/member/month billed annually ($144/year, or $30/month billed monthly) with full-sentence rewrites, plagiarism/AI detection, team style guides, and 2,000 AI prompts/month, while Enterprise offers custom pricing with unlimited AI prompts and BYOK security.

- **Ubiquitous Inline Rewriting & Tone Calibration:** Works natively inside Chrome, Safari, Firefox, Edge, Windows, Mac, Google Docs, MS Office, and mobile keyboards to flag grammar mistakes, rewrite tangled sentences, and shift tone toward confident, empathetic, or executive registers.
- **Specialized AI Agents (AI Grader, Citation Finder & Reader Reactions):** Deploys contextual AI agents that predict how a target audience will react to a draft, locate credible supporting citations, grade essays against rubric criteria, and generate drafts using up to 2,000 monthly prompts on Pro.
- **Grammarly Authorship, AI Detector & Plagiarism Checker:** Scans text against billions of web pages and academic databases for accidental plagiarism, detects AI-generated passages, and logs transparent document provenance via Authorship reports in Google Docs and Word.
- **Team Style Guides, Brand Tones & Knowledge Share:** Enables teams on Pro and Enterprise plans to codify company terminology, ban deprecated jargon, enforce inclusive language, insert shared Snippets, and surface internal company definitions inline.
- **Enterprise Security, DLP & Superhuman Platform Governance:** Protects organizational data with SOC 2 Type 2 attestation, SAML SSO, SCIM lifecycle management, Confidential Mode, Data Loss Prevention controls, Audit Logs API, and customer-managed BYOK encryption.

**Strengths:** Frictionless cross-platform integration works inside virtually every browser, desktop app, email client, and mobile OS without copy-pasting into a separate chatbot.; Consolidating Premium and Business into Grammarly Pro ($12/member/month annual) gives individuals and small teams access to style guides, analytics, and plagiarism/AI detection in one plan.; Grammarly Authorship provides a constructive, transparent audit trail for students and writers to demonstrate human writing integrity alongside responsible AI editing.; Mature enterprise security posture featuring BYOK encryption, Data Loss Prevention, and granular application/domain blocklists.

**Limitations:** Month-to-month billing on Grammarly Pro is steep at $30/member/month compared to the $12/member/month annual commitment ($144 billed upfront).; Core writing intelligence and style rules remain primarily optimized for English dialects (US, UK, Canadian, Australian, Indian) rather than native multilingual grammar checking.; Aggressive inline underlines and pop-up agent cards can feel visually intrusive in dense technical documents or code-heavy web editors unless muted per domain.

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

## Inbox Zero

Inbox Zero is an AI executive assistant layered on top of Gmail and Outlook, built by developer Elie Steinbock (elie2222) and one of the most-starred open-source email projects on GitHub. Once you connect a Google or Microsoft account, it sorts incoming mail into smart categories such as To Reply, Newsletter, Marketing, Calendar, Cold Email and Notification, so you can triage by intent instead of scrolling chronologically. Every message that needs an answer arrives with a pre-written draft based on your past writing and your calendar availability, which you edit and send from the same view.

The tool is unusually broad for an email assistant. It blocks cold outreach before it reaches your inbox, shows you which senders you never open and lets you bulk-unsubscribe and archive them in a few clicks, and produces email analytics about who emails you most and what is clogging your inbox. Because it is open source and self-hostable, developers can inspect the code or run it on their own infrastructure — the company is SOC 2 Type 2 compliant and states your data is never used for AI training.

Inbox Zero also ships a dedicated email app for Gmail and Outlook across web, macOS, Windows and iPhone, is designed to be used from Slack, Telegram or Microsoft Teams, and offers AI meeting notes and pre-meeting briefings on higher tiers. The core app is free; the AI features are billed as a per-user subscription add-on.

**Pricing & Plans:** Freemium with a 7-day free trial on paid tiers. The email app is free; AI plans are billed per user per month (roughly $20 for Starter, $28 for Plus and $40 for Professional on annual billing, with monthly options costing about 20% more). Enterprise pricing with SSO, SCIM and on-premise deployment is available on request.

- **Automatic inbox labelling:** Incoming mail is sorted into categories like To Reply, Newsletter, Cold Email, Calendar and Notification as it arrives, using default rules or categories you define yourself.
- **Pre-drafted replies:** Emails that need a response get a draft written in your tone and referencing your real calendar availability and CRM context, ready to review and send.
- **Cold email blocking and bulk unsubscribe:** Stop cold outreach from ever reaching the inbox, see which newsletters you never read, then unsubscribe and archive them in bulk.
- **Email analytics:** Dashboards reveal who emails you most, which senders dominate your inbox and how your habits change over time so you can act on it.
- **Open source and self-hostable:** The full codebase is public under an open licence, so teams can audit, extend or self-host it, with SOC 2 Type 2 compliance and no AI training on your data.

**Strengths:** Genuinely open source and self-hostable, unlike most AI email assistants; Free core email app plus optional AI add-on keeps entry cost at zero; Combines triage, drafting, unsubscribe, cold-email blocking and analytics in one tool; Works across Slack, Telegram, Teams, web, desktop and mobile

**Limitations:** Best experience requires connecting Google or Microsoft account data; Free tier excludes most AI features, which need a paid per-user plan; Advanced tiers quickly get pricey for large teams

[Profile (Markdown)](https://openaitools.app/tool/inbox-zero.md)

## Frequently Asked Questions

### How do Grammarly and Inbox Zero compare in monthly traffic?

Grammarly has 58,867,412 monthly visits, while Inbox Zero has 89,348. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

Grammarly has a month-over-month growth rate of -1.5%; Inbox Zero has +6.8%.

### How does pricing compare?

Grammarly: Freemium. Free plan ($0/month) includes core grammar and spelling checks, tone detection, and 100 generative AI prompts/month; Grammarly Pro costs $12/member/month billed annually ($144/year, or $30/month billed monthly) with full-sentence rewrites, plagiarism/AI detection, team style guides, and 2,000 AI prompts/month, while Enterprise offers custom pricing with unlimited AI prompts and BYOK security. Inbox Zero: Freemium, Free Trial. Freemium with a 7-day free trial on paid tiers. The email app is free; AI plans are billed per user per month (roughly $20 for Starter, $28 for Plus and $40 for Professional on annual billing, with monthly options costing about 20% more). Enterprise pricing with SSO, SCIM and on-premise deployment is available on request.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [DeepL](https://openaitools.app/tool/deepl) | 95,110,871 | -1.7% | Freemium | Outstanding for context-aware translation and professional writing refinement, but not designed as a dedicated grammar checker. | [.md](https://openaitools.app/tool/deepl.md) |
| 2 | [QuillBot Paraphraser](https://openaitools.app/tool/quillbot-paraphraser) | 36,630,337 | +2.3% | Freemium | Excels at heavy paraphrasing and text rewriting, but offers less seamless inline real-time proofreading across all apps. | [.md](https://openaitools.app/tool/quillbot-paraphraser.md) |
| 3 | [Superhuman](https://openaitools.app/tool/superhuman) | 6,514,241 | +7.9% | Paid | The AI productivity suite with agents, email, and docs that work wherever you do | [.md](https://openaitools.app/tool/superhuman.md) |
| 4 | [LanguageTool](https://openaitools.app/tool/languagetool) | 5,707,795 | -4.2% | Freemium | Provides strong multilingual grammar and style checking across apps, but offers fewer advanced generative AI features. | [.md](https://openaitools.app/tool/languagetool.md) |
| 5 | [ProWritingAid](https://openaitools.app/tool/prowritingaid-com) | 1,623,266 | +17.6% | Freemium, Paid | Delivers deeper manuscript analysis and structural reports, but has a steeper learning curve than Grammarly. | [.md](https://openaitools.app/tool/prowritingaid-com.md) |
| 6 | [Paperpal](https://openaitools.app/tool/paperpal) | 1,111,641 | +1.7% | Freemium | AI academic writing assistant that edits, cites, and checks your manuscript right where you write | [.md](https://openaitools.app/tool/paperpal.md) |
| 7 | [Missive](https://openaitools.app/tool/missive) | 631,353 | +0.2% | Free Trial, Paid | Collaborative inbox and email management for teams | [.md](https://openaitools.app/tool/missive.md) |
| 8 | [Hemingway Editor](https://openaitools.app/tool/hemingway-editor) | 605,169 | -8.6% | Free Trial, Paid, Free | Highlights readability and sentence complexity visually, but lacks automated grammar correction and browser-wide extension support. | [.md](https://openaitools.app/tool/hemingway-editor.md) |
| 9 | [Spark Mail](https://openaitools.app/tool/spark-mail) | 435,229 | -13.5% | Freemium, Free Trial | Smart, focused email with AI help — for individuals and teams | [.md](https://openaitools.app/tool/spark-mail.md) |
| 10 | [Wordtune](https://openaitools.app/tool/wordtune) | 368,771 | -5.8% | Freemium, Free Trial | Great for sentence-level tone adjustments and rewriting, but less comprehensive for standalone grammar rules and style guides. | [.md](https://openaitools.app/tool/wordtune.md) |

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Source: https://openaitools.app/compare/grammarly-vs-inbox-zero

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