How to Test Your Monitor: Complete Guide
Whether you just bought a new monitor or checking an existing one, proper testing ensures you get the quality you paid for. This comprehensive guide walks you through every test you should run.
1 Before You Start
🛠️ Preparation Checklist
- ✓ Clean your screen - Use a microfiber cloth to remove dust, fingerprints, and smudges. Dirt can be mistaken for dead pixels.
- ✓ Warm up the display - Run your monitor for at least 30 minutes before testing. Cold LCD panels may show temporary defects.
- ✓ Optimal lighting - Test in a moderately lit room. Too bright or too dark affects your perception.
- ✓ Native resolution - Set your monitor to its native resolution (e.g., 2560x1440 for QHD, 3840x2160 for 4K).
- ✓ Default settings - Reset monitor settings to factory defaults for accurate baseline testing.
- ✓ Close other apps - Close background applications to ensure accurate performance measurements.
⚠️ Important Notes
- • New monitors: Test immediately upon arrival (within return period - usually 14-30 days)
- • Used monitors: Request testing before purchase, or include "tested working" clause in agreement
- • Warranty claims: Document all defects with photos and save test results
2 Essential Tests (Must Do)
🔴 Dead Pixel Test
Priority: CRITICAL | Time: 3-5 minutes
What it checks: Individual pixels that are permanently off (dead) or stuck displaying a single color.
How to test:
- Enter fullscreen mode
- Cycle through all 8 colors: White, Black, Red, Green, Blue, Yellow, Magenta, Cyan
- Look carefully at the entire screen for spots that don't match the background
- Pay extra attention to corners and edges
- Take at least 30 seconds per color
What to look for:
- • Dead pixel: Always black on all colors
- • Stuck pixel: Always red, green, or blue (subpixel stuck)
- • Hot pixel: Always white or very bright
✅ Acceptable Result:
0 dead/stuck pixels (ideal). According to ISO 13406-2 Class II standard, up to 2 bright pixels and 2 dark pixels are considered acceptable by manufacturers, but you should still request replacement if found within return period.
⬛ Uniformity Test
Priority: HIGH | Time: 2-3 minutes
What it checks: Backlight bleeding, IPS glow, and color/brightness uniformity across the screen.
How to test:
- Test in a completely dark room
- Set brightness to 50%
- Display 0% gray (pure black)
- Look for bright spots or uneven brightness, especially in corners
- Test at 5%, 10%, 25%, 50% grays as well
✅ Acceptable Result:
Slight corner glow is normal for IPS panels. Moderate backlight bleed is common but shouldn't be excessive. VA panels typically have better uniformity than IPS.
⚡ Refresh Rate Test
Priority: MEDIUM | Time: 1-2 minutes
What it checks: Verifies your monitor is actually running at its advertised refresh rate (60Hz, 144Hz, 240Hz, etc.).
How to test:
- Set your monitor to maximum refresh rate in Windows/macOS display settings
- Run the test for at least 30 seconds
- Check the measured FPS matches your target (±2 FPS tolerance)
- Watch for frame skips (should be 0 or very minimal)
- Stability should be 95%+ (low standard deviation)
✅ Acceptable Result:
FPS matches your set refresh rate within ±2 FPS. Frame skips should be 0-5 over 30 seconds. If you're getting significantly lower FPS, check your cable (use DisplayPort for >60Hz).
3 Advanced Tests (Recommended)
🏃 Response Time
Tests motion clarity and ghosting. Critical for gaming and fast-paced content.
Start Test →🌓 Contrast Ratio
Checks ability to differentiate between dark and light tones. Important for image quality.
Start Test →📊 Gamma Test
Verifies proper gamma curve (usually 2.2). Essential for color-critical work.
Start Test →🌡️ Color Temperature
Tests white point accuracy. Standard is 6500K (D65) for most content.
Start Test →4 Specialized Tests (Use Case Specific)
🎮 For Gamers
Input Lag Test, Response Time, Refresh Rate, Viewing Angle
🎨 For Designers/Photographers
Gamma, Color Temperature, Uniformity, Gradient Banding, HDR
📺 For Media Consumption
Contrast Ratio, Backlight Bleed, HDR, Flicker Test
5 Interpreting Your Results
📊 Scoring Guide
Monitor performs at or above specifications. No defects found.
Minor issues within acceptable tolerances. Typical for the price range.
Noticeable issues but usable. Consider replacement if within return period.
Significant defects. Request replacement immediately.
🎯 What's "Normal"?
- ✓ IPS Glow: Some corner glow on IPS panels when viewing dark content is normal, especially at angles.
- ✓ Minor backlight bleed: Slight brightness variations in corners are common on most monitors.
- ✓ Response time variance: Real response time is usually 2-3x advertised (e.g., "1ms" monitors often measure 3-5ms).
- ✗ Dead/stuck pixels: NOT normal. Any visible pixel defects warrant replacement.
- ✗ Severe backlight bleed: Large bright spots visible during regular use indicate manufacturing defect.
6 When to Request a Replacement
Don't settle for a defective monitor. These issues justify immediate replacement:
❌ Immediate RMA
- • Any visible dead or stuck pixels
- • Severe backlight bleed visible during normal use
- • Incorrect refresh rate (can't reach advertised Hz)
- • Persistent burn-in on new displays
- • Excessive color banding
- • Hardware damage (scratches, cracks)
⚠️ Consider RMA
- • Moderate backlight bleed affecting viewing
- • Significant color uniformity issues
- • PWM flicker causing eye strain
- • Coil whine or buzzing sounds
- • Flickering at high refresh rates
- • Uneven brightness across screen
💡 RMA Tips
- • Document defects with photos and videos (use phone camera)
- • Save test results from FreeScreenTest as evidence
- • Contact manufacturer within return/warranty period
- • Be polite but firm - pixel defects are NOT acceptable
- • Request advanced RMA (new monitor before returning old one)
- • Some manufacturers allow 1 free replacement within 30 days
7 Best Practices & Tips
🕐 Testing Schedule
- Day 1: Dead pixel, uniformity, refresh rate
- Week 1: Full test suite
- Monthly: Dead pixel check (OLED users)
- Yearly: Burn-in test (OLED), color calibration
📸 Documentation
- • Use phone camera for defect photos (cameras show what eyes see)
- • Save screenshots of test results
- • Record model number and serial number
- • Keep purchase receipt and warranty info
🎯 Accuracy Tips
- • Use fullscreen mode for all tests
- • Disable Windows Night Light / f.lux
- • Turn off ambient lighting sensors
- • Use native resolution
- • Test at multiple brightness levels
🔧 Common Fixes
- • Stuck pixel: Try pixel fixing videos (30 min)
- • Low refresh rate: Check cable quality (use DP 1.4)
- • Poor colors: Reset to factory settings
- • Flickering: Disable variable refresh rate (VRR)
Ready to Test Your Monitor?
Start with our essential tests - it takes less than 10 minutes.