ScreenTools
Free browser-based tools for screen work — PPI, pixels, aspect ratios, dead pixels, device specs, and screen-size planning. No signup required.
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Device Specs Database
Verified screen specs for 69+ phones, tablets, laptops, and monitors. Filter by brand, OS, year, and screen size to compare devices side-by-side.
- 69+ verified devices
- Filter by brand / year / OS
- Cross-linked with ruler
Dead Pixel Test
Cycle full-screen solid colors to spot dead, stuck, and hot pixels on any monitor, laptop, phone, or tablet. Includes a Stuck Pixel Fixer mode.
- 9 solid-color screens
- Stuck pixel fixer mode
- Full-screen + keyboard shortcuts
Aspect Ratio Calculator
Calculate aspect ratio from pixel dimensions or find a missing width/height for a known ratio. Includes 8 common presets — 16:9, 4:3, 1:1, 9:16, 21:9, 3:2, 2:3, and 2.39:1 cinema.
- 8 common ratio presets
- Width × height ↔ ratio
- Shareable URL + copy result
Pixel Converter
Convert pixels to millimeters, centimeters, and inches at any DPI. Five presets cover web (96), Mac legacy (72), and print (150/300/600).
- 4-unit live conversion
- 5 DPI presets + custom
- Shareable URL + copy
Screen Size Calculator
Convert diagonal + aspect ratio to physical width × height. Compare two to four screens at true scale. Built-in THX, SMPTE, and 4K viewing-distance recommendations.
- 4 modes (diagonal / compare / viewing distance / preset)
- 8 aspect ratios + 15+ device presets
- Multi-screen visual compare at true scale
PPI Calculator
Calculate pixels-per-inch from any screen size and resolution. Check Retina threshold at your viewing distance, or reverse the math to find the pixels you need for sharp print at 300 DPI.
- Auto-detect this device
- 4 modes: screen / print / compare
- Retina threshold + viewing distance
Color Picker
Pick any color on screen with the Eyedropper API, convert HEX/RGB/HSL/HSV, save palette.
- Eyedropper API + manual input
- Four-format live conversion
- Saved palette + shareable URL
HEX Converter
Convert HEX ↔ RGB ↔ HSL ↔ HSV; batch mode handles a color list at once.
- Four-format conversion
- Batch mode (paste a list)
- Copy buttons + shareable URL
Contrast Checker
WCAG 2.x color contrast ratio + AA/AAA pass-fail for normal and large text.
- Four WCAG grades (AA/AAA × normal/large)
- Live text preview at 16px + 24px
- Any input format + swap button
Why ScreenTools?
Works on Any Screen
Desktop, laptop, tablet, or phone — ScreenTools utilities work on any device with a modern web browser.
No Download Required
Open the tool you need and start working. No apps, plugins, accounts, or installation steps.
Screen-Aware Utilities
Use verified device specs, display math, and browser-side calculations for practical screen decisions.
20 Languages
Available in English, Chinese, Japanese, Korean, Spanish, French, German, and 13 more languages.
How It Works
Open the Tool
Visit screentools.online and choose the calculator, screen test, device lookup, or sister-site measurement tool you need.
Enter or Select Data
Type dimensions, pick a device preset, run a screen test, or open the relevant sister-site tool for physical measurement.
Use the Result
Copy the result, compare devices, share the URL, or continue into a related guide when you need more context.