Our Mission
Screen DPI Checker was created to provide designers, developers, and digital professionals with an accurate, easy-to-use tool for measuring their display's pixel density and physical dimensions. We believe that understanding your screen's specifications is essential for creating pixel-perfect designs and developing responsive applications.
Why We Built This Tool
Modern displays come in a wide variety of sizes and resolutions, from standard 1080p monitors to ultra-high-resolution 4K and 5K displays. This diversity makes it challenging for professionals to:
- Accurately preview how designs will appear on different devices
- Test responsive layouts across various screen densities
- Understand the true pixel density of their workspace
- Make informed decisions when purchasing new displays
Operating systems typically report a standardized DPI value (like 96 or 72) regardless of your actual screen density. This legacy approach doesn't reflect the true physical characteristics of modern displays. Our tool calculates your actual, physical pixel density using precise calibration methods.
How It Works
Automatic Detection
When you visit our website, the tool automatically detects your screen resolution, device pixel ratio, browser type, and operating system. This information is processed entirely in your web browser — nothing is sent to our servers.
Calibration Methods
We offer two calibration methods to determine your screen's physical size:
Credit Card Calibration (Recommended)
This method uses a standard credit card as a physical reference. Credit cards follow the ISO/IEC 7810 ID-1 standard, measuring exactly 85.6mm × 53.98mm. By adjusting an on-screen rectangle to match your physical card, the tool can calculate your screen's DPI with exceptional accuracy.
Manual Entry
If you know your screen's diagonal size (typically listed in product specifications), you can enter it directly. The tool then calculates your DPI using the Pythagorean theorem based on your screen resolution.
Privacy-First Design
All calculations are performed locally in your browser using JavaScript. We do not collect, store, or transmit any personal information or measurement data to our servers. Your privacy is our priority.
Who Uses This Tool
UI/UX Designers
Create pixel-perfect mockups and accurately preview designs across different screen densities. Understand how interfaces will appear on various devices before deployment.
Web & App Developers
Test responsive layouts, ensure images scale correctly, and understand device pixel ratios for optimal user experiences across all screen types.
Print & Graphics Professionals
Bridge the gap between screen and print resolution. Understand how digital assets will translate to physical media by knowing your display's true pixel density.
Hardware Buyers
Make informed purchasing decisions by understanding screen specifications. Compare your current display with potential upgrades based on actual pixel density.
Accuracy and Reliability
We take accuracy seriously. Our tool uses:
- ISO Standard Reference: Credit card calibration based on international standards
- Precise Calculations: Mathematical formulas that account for device pixel ratio and resolution
- Browser Compatibility: Testing across all major browsers to ensure consistent results
- Regular Updates: Continuous improvement based on user feedback and technological changes
Free and Always Will Be
Screen DPI Checker is and will remain completely free to use. We believe essential professional tools should be accessible to everyone, regardless of budget.
To support the hosting and maintenance of this tool, we display non-intrusive advertisements and include affiliate links to quality products we genuinely recommend. These monetization methods allow us to keep the tool free while maintaining it for the long term.
Open to Feedback
We're constantly working to improve Screen DPI Checker. If you have suggestions, encounter issues, or want to share how you use the tool, we'd love to hear from you. Please reach out through our contact page.
Technical Information
Browser Compatibility
This tool works in all modern web browsers including:
- Google Chrome (version 90+)
- Mozilla Firefox (version 88+)
- Safari (version 14+)
- Microsoft Edge (version 90+)
- Opera (version 76+)
Mobile Support
While the tool functions on mobile devices, we recommend using it on desktop computers for the most accurate calibration. The credit card method works best on larger screens where precise adjustments are easier to make.
Technology Stack
Built with pure web technologies for maximum compatibility and performance:
- Vanilla JavaScript (no frameworks or dependencies)
- HTML5 for semantic structure
- CSS3 for responsive, accessible design
- Static hosting for instant loading
Future Development
We're exploring additional features including:
- Comparison mode for multiple displays
- Exportable reports with your screen specifications
- Additional calibration methods using common objects
- Historical data visualization for resolution trends
Contact Information
Have questions or feedback? We're here to help:
Email: support@screendpichecker.com
Response Time: We typically respond within 24-48 hours
Attribution
Screen DPI Checker is an independent project created to serve the design and development community. We are not affiliated with any hardware manufacturers or software companies.
Thank you for using Screen DPI Checker. We hope this tool makes your work easier and more accurate.