Your spreadsheet data never leaves your computer
Local AI catches Excel formula errors — offline, private, instant. No cloud uploads, no data sharing, no compromises.
Other tools upload your data to the cloud
Most spreadsheet checkers send your financial data to remote servers. CellSentry keeps everything on your machine.
Cloud-based tools
- Data uploaded to third-party servers
- Requires internet connection
- Privacy policies can change
- Sensitive data leaves your network
CellSentry
- All analysis runs on your computer
- Works completely offline
- No data ever sent anywhere
- Your files stay in your control
Everything you need to catch formula errors
A hybrid approach: deterministic rules for speed, local AI for depth.
Rule Engine
17 built-in rules catch common formula errors — missing references, circular dependencies, inconsistent ranges, and more.
AI Analysis
Fine-tuned local language model understands complex formula patterns and catches errors that rules alone miss.
Real-time Monitoring
Watches your Excel files and automatically scans when you save. Results appear instantly in the floating widget.
Report Export
Generate HTML and Markdown reports of all detected issues. Share findings with your team or keep for your records.
How it works
Set it up once, then forget about it. CellSentry runs silently in the background.
Save your Excel file
Just work normally in Excel or WPS. CellSentry watches for file changes in the background.
CellSentry analyzes locally
The rule engine and AI model run entirely on your machine. Nothing is uploaded anywhere.
Review results in the widget
A Grammarly-style floating widget shows issues right next to your spreadsheet. Click to navigate to the problem cell.
Simple, transparent pricing
Start free with the rule engine. Upgrade to Pro for AI-powered analysis.
Free
- 17-rule error detection engine
- 3 scans per day
- Floating widget UI
- HTML & Markdown reports
- Windows & Mac
Pro
or $99.99/year (save 17%)
- Everything in Free
- AI-powered analysis (local LLM)
- Unlimited scans
- Priority formula patterns
- Excel Add-in integration
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Frequently asked questions
Yes, 100%. CellSentry runs entirely on your computer. The AI model is downloaded once and runs locally. No data is ever sent to any server — not even to us. Your spreadsheets never leave your machine.
The rule engine detects 17 types of common errors including broken references, inconsistent ranges, division by zero risks, hardcoded values in formulas, circular dependencies, and more. The Pro AI model catches complex patterns that rules alone miss.
Yes, fully offline after the initial setup. The AI model is downloaded once (~1GB), then everything runs without an internet connection. Perfect for air-gapped environments or when traveling.
CellSentry works on both Windows 10+ and macOS. The Mac version uses Apple's Metal acceleration for fast AI inference. Windows is the primary target, but Mac is fully supported.
Absolutely. The Free tier includes the full 17-rule engine with 3 scans per day — no credit card required, no time limit. Upgrade to Pro only if you want AI-powered analysis and unlimited scans.
Ready to protect your spreadsheets?
Download CellSentry and start catching formula errors in minutes. No account required.