WebInfer

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4.2 / 5

Proofr

Free, local Grammarly alternative that never sees your writing

Useful
Zero Cost
Privacy

The Problem

Grammarly costs $30/month, and cloud services see all your writing

Current Solutions (Not Great)

Pay for Grammarly, use free tier with limits, or write poorly

Who Needs This

Writers, students, professionals who write frequently

Real-time grammar, spelling, and tone analysis without the $30/month subscription or privacy concerns. Your writing never leaves your browser—perfect for sensitive documents, legal work, or anyone who values privacy.

Honest Take

Solid opportunity—Grammarly is expensive and people hate subscriptions. But competing with Grammarly's polish and distribution is hard. The privacy angle is real for lawyers, healthcare, and enterprise. Best bet: target a specific vertical (legal writing, medical notes) rather than going broad.

Monetization Ideas
Ways to turn this into revenue

Freemium

Free basic, $5-15/mo for pro

Subscription

$5-29/month or $49-199/year

One-Time Purchase

$9-49 per license

Lifetime Deal

$29-99 lifetime access

Features
Key features that make this app valuable
  • Real-time grammar and spelling checks
  • Tone analysis (formal, casual, confident)
  • Clarity improvements
  • Word choice suggestions
  • Works offline after setup
  • No data ever leaves browser
Build Prompt
Use this prompt with an AI assistant to start building
Build a React PWA called 'Proofr' using WebInfer for AI inference. Main UI: split pane with editable textarea on left, suggestions panel on right. Use streamText with debounced input (500ms) to analyze text as user types. Use generateObject to return { issues: [{ type: 'grammar' | 'spelling' | 'clarity' | 'tone', text: string, suggestion: string, startIndex: number, endIndex: number }], overallScore: number, toneAnalysis: string }. Highlight issues inline with colored underlines (red=grammar, blue=clarity, purple=tone). Click issue to see explanation and accept/reject fix. Add tone selector (formal, casual, academic, friendly) that adjusts suggestions. Stats footer showing word count, reading time, readability score. Export as clean text or markdown.
Score Breakdown
Pain
Clarity
Demo
Build
Share
Revenue

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