๐ Text Clarity Test
Test text rendering quality, font clarity, and subpixel rendering. Essential for programmers, writers, and anyone who works with text.
๐ก Why This Test?
Text clarity determines how crisp and readable text appears at various sizes. It depends on display resolution (PPI), subpixel rendering (ClearType on Windows), scaling settings, and panel quality. Poor text rendering causes eye strain, especially during long coding or writing sessions.
This test evaluates font readability from 6px to 24px, checks ClearType/subpixel antialiasing effectiveness, tests monospace character distinction (critical for programming), and detects scaling issues. High-resolution displays (>150 PPI) with proper subpixel rendering deliver exceptional text clarity.
โ What You'll Check:
- Smallest readable font size (6px, 8px, 10px, 12px)
- Subpixel rendering quality (colored fringes test)
- Monospace character distinction (0/O, il1|, rn/m)
- ClearType/antialiasing effectiveness
- Display scaling impact on text sharpness
๐ How to Use This Test
- Enable ClearType on Windows (Settings โ Display โ ClearType text)
- Scroll through font sizes and note the smallest you can read comfortably
- Check subpixel rendering section for colored edges (red/blue fringes)
- Test monospace fonts and verify you can distinguish 0/O, il1|, rn/m
- Look at large text (48px) closely for antialiasing quality
- Check your device pixel ratio (DPR) at the bottom
- Save your results noting the smallest readable size
๐ก Tip: Ideal readability: 8px or smaller. Use 100% or 200% scaling (not 125%/150%). Higher PPI displays (>150) show sharper text. Enable ClearType on Windows, macOS handles this automatically. Adjust brightness to comfortable levels (not max).
๐ Font Size Clarity
Check readability at different font sizes. All text should be crisp and clear.
๐ค Font Family Comparison
Compare serif vs sans-serif fonts. Check which is more readable for you.
Sans-Serif (Gothic)
12px: Programming requires clear monospace fonts
14px: Programming requires clear monospace fonts
16px: Programming requires clear monospace fonts
18px: Programming requires clear monospace fonts
Serif (Myeongjo)
12px: Programming requires clear monospace fonts
14px: Programming requires clear monospace fonts
16px: Programming requires clear monospace fonts
18px: Programming requires clear monospace fonts
๐ Multilingual Clarity
Test text rendering quality across different languages and scripts.
๐บ๐ธ English
The quick brown fox jumps over the lazy dog.
ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
0123456789 !@#$%^&*()_+-=[]|;:'",./?
๐ฏ๐ต ๆฅๆฌ่ช (Japanese)
ใใใฏใซใปใธใจ ใกใใฌใใ
ใใใใใ ใใใใใ ใใใใใ
ใขใคใฆใจใช ใซใญใฏใฑใณ ใตใทในใปใฝ
ๆผขๅญใในใ: ๆฅๆฌ่ช่กจ็คบ็ขบ่ช
๐จ๐ณ ไธญๆ (Chinese)
ๅฟซ้็ๆฃ่ฒ็็ธ่ทณ่ฟๆ็
็ฎไฝไธญๆ๏ผๅบๅๆๆๅ ๏ผ็ๆฏๅฐไธ้
็น้ซไธญๆ๏ผๅบๅๆๆๅ ๏ผ็ๆฏๅฐไธ้
ไธไบไธๅไบๅ ญไธๅ ซไนๅ
๐ฌ Subpixel Rendering Test
LCD screens use RGB subpixels. If you see colored fringes, your screen uses subpixel rendering. Look closely at the edges of letters.
๐ป Monospace Font Test (Programming)
Test clarity of monospace fonts used in code editors. Characters should be easily distinguishable.
const fibonacci = (n) => {
if (n <= 1) return n;
return fib(n-1) + fib(n-2);
};
// Test characters: 0O o8B il1| ,;:.
console.log(fibonacci(10));
const fibonacci = (n) => {
if (n <= 1) return n;
return fib(n-1) + fib(n-2);
};
// Test characters: 0O o8B il1| ,;:.
console.log(fibonacci(10));
โ Text Clarity Checklist
Rate your screen's text rendering quality.
๐ก Tips for Better Text Clarity
- โข Enable ClearType on Windows (Control Panel โ Appearance โ ClearType)
- โข macOS automatically optimizes font rendering
- โข Use 100% or 200% scaling (avoid 125%, 150%)
- โข Higher PPI displays (>110 PPI) show sharper text
- โข Adjust brightness to comfortable level (not too bright)
๐ Resolution Scaling Test
Check if your display scaling is optimal. Non-integer scaling (125%, 150%) can cause text blur.
๐ง Common Issues & Solutions
๐ค "Text looks blurry/fuzzy at 100% Windows scaling" (ClearType, subpixel rendering)
What's happening: ClearType disabled or misconfigured. ClearType: Windows subpixel antialiasing uses RGB subpixels to triple horizontal resolution for text. Each pixel = 3 subpixels (red, green, blue stripes). ClearType renders text using subpixels for sharper edges. Disabled: Text uses grayscale antialiasing (blurrier) or no antialiasing (jagged). Check: Control Panel โ Appearance โ ClearType Text โ Wizard shows tuning options. Some users disable it (preference) but most benefit from it on LCD displays.
Browser/app-specific issues: Chrome/Edge use DirectWrite (respects ClearType). Firefox historically used different rendering (now also DirectWrite). Some apps bypass ClearType: Java apps, old Win32 apps, some Electron apps. Font rendering differences: Chrome sharp, Firefox slightly different weight, native Windows apps (Notepad, WordPad) sharpest. Browsers use different font rendering engines: Blink (Chrome), Gecko (Firefox), WebKit (Safari). Sub-pixel layout matters: Most LCDs: RGB stripe (red left, blue right). Some: BGR (blue left, red right). ClearType assumes RGB - BGR causes color fringing.
โ Solution: Enable ClearType: Windows 10/11 โ Settings โ Search "ClearType" โ Adjust ClearType text โ Run tuning wizard (5 screens, choose clearest text). Registry tweak for stronger ClearType: HKEY_CURRENT_USER\Control Panel\Desktop โ FontSmoothing = 2 (enabled), FontSmoothingType = 2 (ClearType), FontSmoothingGamma = 1400-1800 (experiment, default 1400). macOS: No ClearType equivalent, uses grayscale antialiasing (looks different, not necessarily worse). Linux: FreeType + fontconfig, can emulate ClearType with rgb/bgr hinting. For best results: Use native Windows apps for text work, adjust ClearType tuning to your specific monitor.
๐ "Red/blue color fringes around text edges" (BGR vs RGB subpixel layout)
What's happening: Subpixel layout mismatch. Standard LCD: RGB (red-green-blue left to right). Some displays: BGR (blue-green-red). Rare: vertical RGB, PenTile (OLED phones). ClearType assumes RGB: Renders assuming red on left. On BGR display: Blue rendered where red should be โ colored fringing. Noticeable on dark text on light background: Red fringe on left edge, blue on right (or reversed if BGR). Which panels are BGR? Some older Samsung monitors, some laptop panels (Dell, HP), some TVs when used as monitors.
Detecting subpixel layout: View text at 200-300% zoom in browser, look at edge of black text on white - see red/blue subpixels. Or use magnifying glass. Online test: Display magnified text with ClearType, check if left edge is red (RGB) or blue (BGR). macOS font rendering: Uses grayscale antialiasing (no subpixel rendering) so BGR/RGB irrelevant - avoids color fringing entirely but text less sharp than ClearType. iPhone/iPad OLED: PenTile (diamond) subpixel layout, iOS compensates in rendering.
โ Solution: Change ClearType subpixel order: Windows registry โ HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Avalon.Graphics โ PixelStructure โ Set to 1 (RGB, default) or 2 (BGR). Restart apps/reboot. No native Windows UI for this - must use registry. Alternative: Disable ClearType if fringing bothers you - use grayscale antialiasing (less sharp but no color). Third-party tools: MacType (Windows font rendering replacement), can set BGR mode. For external monitors: Some TVs report BGR, check TV model specs or test manually. Professional monitors (EIZO, BenQ) usually RGB.
๐ "Text blurry at 125%/150% scaling but sharp at 100%" (Fractional DPI scaling)
What's happening: Integer scaling (100%, 200%): 1 logical pixel = 1 or 2 physical pixels, sharp. Fractional scaling (125%, 150%, 175%): 1 logical pixel = 1.25/1.5/1.75 physical pixels - requires interpolation (blurring). Windows 10/11: Renders UI at higher resolution then downscales using bilinear/bicubic filtering โ blur. Affects: GDI apps (old Windows programs), some Win32 apps. Modern DPI-aware apps handle better but still not pixel-perfect.
Why fractional scaling exists: 1440p 27" (109 PPI) comfortable at 100% but 4K 27" (163 PPI) too small at 100%, needs 150-200% scale. Apple Retina: 2x scaling always (220 PPI displays rendered at 110 PPI equivalent) - always sharp. Windows: Fractional needed for 1080p/1440p/4K variety. Which apps affected most: Chrome/Edge OK (DPI-aware). Old apps (Adobe CS5, older IDEs, Win32 controls) very blurry. Text editors (VS Code, Sublime) mostly OK. Office 2016+ DPI-aware. Office 2013 and older blurry.
โ Solution: Use integer scaling only: 100% for <120 PPI displays (1080p 24", 1440p 27"), 200% for high-PPI (4K 24" = 184 PPI, readable at 200%). Avoid 125%/150%/175% if text clarity critical. Windows 11 improved fractional scaling vs Windows 10. Enable "Fix scaling for apps" in Settings โ Display โ Advanced scaling โ "Let Windows try to fix apps." Increase monitor size instead of scaling: 4K 32" (138 PPI) at 100% vs 4K 27" (163 PPI) at 150%. For programming: 27" 1440p at 100% ideal (109 PPI, sharp text, enough space). macOS: No fractional scaling issues due to 2x rendering.
๐ "4K monitor makes text tiny, can't read without scaling" (High PPI requires scaling)
What's happening: PPI determines physical text size. 24" 1080p: 92 PPI, 12pt font = 1.6mm tall. 27" 4K: 163 PPI, 12pt font = 0.9mm tall (too small for many). 32" 4K: 138 PPI, 12pt font = 1.1mm tall (borderline). Human vision: 20/20 eyesight can resolve ~0.3mm at 20" distance (300 PPI limit). Comfortable reading: 1.2-1.6mm text height = 90-120 PPI range optimal. High PPI displays need scaling to achieve comfortable text size.
Scaling vs resolution tradeoff: 4K 27" at 200% scale = looks like 1080p 27" (same text size) but sharper (double pixels). 4K 27" at 150% scale = between 1080p and 1440p readability, but fractional scaling blur. 4K 32" at 125% or 100% = readable but monitor very large on desk. Apple: 27" 5K iMac (218 PPI) at 2x = looks like 109 PPI (perfect) with Retina sharpness. Windows: Lacks 5K support, relies on fractional scaling. Young eyes vs aging eyes: People 20-30: Comfortable with 140+ PPI at 100%. Age 40+: Need larger text, 100-110 PPI optimal.
โ Solution: Match monitor size to resolution for desired PPI. Ideal combos: 24" 1080p (92 PPI), 27" 1440p (109 PPI), 32" 4K (138 PPI), 43" 4K (103 PPI). All usable at 100% scale with sharp text. For existing 4K 27": Use 150% scale (accept slight blur) or increase font size in apps instead of system scaling. Browser: Ctrl+Plus to zoom text. VS Code: Editor zoom level. Windows: Settings โ Accessibility โ Text size (scales text only, not UI). For perfect sharpness: 27" 1440p at 100% best compromise (sharp + readable). Aging vision: Larger monitors at same resolution = bigger text without scaling.
๐ "Text looks different in Chrome vs Firefox vs native apps" (Rendering engines, font hinting)
What's happening: Different text rendering stacks. Windows native (GDI/DirectWrite): ClearType subpixel, follows Windows font settings. Chrome/Edge (Blink + DirectWrite): Similar to Windows, respects ClearType. Firefox (Gecko + DirectWrite): DirectWrite but different font weight/rendering. Electron apps: Based on Chromium, should match Chrome but some apps customize rendering (VS Code, Slack). Java apps: Own rendering, often ignores ClearType (ugly text).
Font hinting differences: Hinting: Instructions in font files to align to pixel grid. Windows: Aggressive hinting (sharp but slightly distorted letterforms). macOS: Light hinting (preserves letter shape, slightly fuzzier). Linux FreeType: Configurable (can match Windows or macOS). Browser rendering: Chrome uses Skia (graphics library), Firefox uses Gecko renderer. Result: Same font, same size, different appearance across browsers. DirectWrite vs GDI: Old apps (pre-2010) use GDI (lighter antialiasing), modern apps use DirectWrite (heavier antialiasing, thicker looking).
โ Solution: Stick to one app ecosystem if consistency matters (all Chrome-based, or all native Windows apps). Enable DirectWrite in browsers: Chrome/Edge use it by default. Firefox: about:config โ gfx.webrender.all = true, gfx.font_rendering.cleartype_params.rendering_mode = 5 (natural). Adjust font weight in CSS: font-weight: 500 instead of 400 (slightly thicker, closer to native). For programming: Use VS Code with Consolas or Cascadia Code font (designed for ClearType). macOS migration: macOS text looks "thinner" than Windows - adjust font-weight in apps or use thicker fonts. Accept differences: Browsers will never match native Windows rendering exactly due to different engines.