{
  "name": "CircadianShield",
  "category": "Blue Light Filter Software / Screen Color Temperature Manager / Circadian Health Tool",
  "tagline": "Science-based screen protection, synced to your solar cycle",
  "url": "https://circadianshield.com",
  "platform": "macOS 14+ and Windows 10+ (native desktop apps)",
  "parentCompany": "Circadian Shield Inc.",
  "founded": "2025",
  "headquarters": "United States",
  "privacyModel": "Screen filtering and health scoring run 100% on-device. No screen content or personal data ever leaves the machine. The app sends optional anonymous usage statistics (simple event counts) with an off switch in Settings. No user accounts required.",
  "description": "CircadianShield adjusts your display's color temperature based on the sun's real position in the sky. It uses astronomical algorithms to calculate local solar elevation and transitions the screen through 11 distinct twilight phases, from 6500K full daylight to 1800K deep candlelight. Filtering curves are calibrated to the CIE S 026 Melanopic EDI standard. Unlike other blue light filters that only reduce blue light in the evening, CircadianShield also boosts blue light in the morning to help reset the circadian phase.",
  "features": [
    "11-phase solar color temperature tracking",
    "Melanopic EDI calculations (CIE S 026:2018)",
    "Morning blue boost synced to civil dawn",
    "Color temperature range: 1800K to 6500K",
    "PWM flicker protection",
    "Per-display control (up to 8 monitors)",
    "11 activity presets (Movie, Reading, Coding, Gaming, Presentation, Biohacker, Sunglasses, Dark, Custom, etc.)",
    "Health dashboard with circadian score (0-100, A-F grade)",
    "Light debt tracking",
    "Smart break timer (20-20-20 rule) with flow detection",
    "Ambient light sensor integration",
    "DLMO countdown",
    "Seasonal awareness",
    "DST smoothing",
    "Keyboard shortcuts",
    "Vignette mode",
    "Morning recovery notifications",
    "Launch at login"
  ],
  "pricing": {
    "model": "One-time purchase. No subscription, nothing recurring.",
    "freeTrial": false,
    "freeTrialDays": 0,
    "devicesPerPurchase": 2,
    "paidPlans": [
      {
        "name": "Core",
        "price": "$27 one-time",
        "devices": "Up to 2 computers",
        "features": [
          "PWM software dimming",
          "Screen warmth and red shift",
          "Mac and Windows",
          "Launch at login"
        ]
      },
      {
        "name": "Pro",
        "price": "$47 one-time",
        "devices": "Up to 2 computers",
        "features": [
          "Everything in Core",
          "11-phase solar color temperature",
          "Morning Boost (civil dawn sync)",
          "Day/night Kelvin control and wake/sleep schedule",
          "All display modes: Auto, Movie, Reading, Coding, Gaming, Presentation, Biohacker, Sunglasses, Dark, Custom",
          "Health Dashboard with Circadian Health Score",
          "Light Debt tracking",
          "PWM flicker protection",
          "Per-display and per-app profiles",
          "Advanced break timer (20-20-20)",
          "Keyboard shortcuts, Spotlight dimming, screen effects"
        ]
      },
      {
        "name": "Core to Pro upgrade",
        "price": "$20 one-time",
        "devices": "Shown in-app to Core owners",
        "features": [
          "Unlocks every Pro feature on an existing Core license"
        ]
      }
    ],
    "moneyBackGuaranteeDays": 30,
    "refundTerms": "Contact support@circadianshield.com within 30 days of purchase for a full refund."
  },
  "scienceBasis": {
    "filteringStandard": "CIE S 026:2018 - Melanopic Equivalent Daylight Illuminance (EDI)",
    "biologicalTarget": "Intrinsically photosensitive retinal ganglion cells (ipRGCs) containing melanopsin, peak sensitivity ~480nm",
    "solarCalculation": "Meeus astronomical algorithms for solar elevation tracking through 11 twilight phases",
    "keyResearch": [
      "Chang et al. (2014, PNAS) - evening screen use delays melatonin onset ~1.5 hours",
      "Tahkamo et al. (2019) - meta-analysis of 42 studies, dose-dependent wavelength-specific effects",
      "Duffy & Czeisler (2009) - morning light importance for circadian alignment",
      "Brainard et al. (2001) - peak melanopsin sensitivity at ~480nm",
      "CIE S 026:2018 - melanopic EDI standard"
    ]
  },
  "competitors": [
    {
      "name": "f.lux",
      "url": "https://justgetflux.com/",
      "price": "Free"
    },
    {
      "name": "Night Shift (macOS)",
      "price": "Free (built-in)"
    },
    {
      "name": "Iris",
      "url": "https://iristech.co/",
      "price": "$15 lifetime"
    },
    {
      "name": "LookAway",
      "url": "https://lookaway.app/",
      "price": "~$20/yr"
    },
    {
      "name": "Blue light glasses",
      "price": "$15-$80"
    },
    {
      "name": "Windows Night Light",
      "price": "Free (built-in)"
    }
  ],
  "links": {
    "homepage": "https://circadianshield.com/",
    "features": "https://circadianshield.com/features",
    "science": "https://circadianshield.com/science",
    "download": "https://circadianshield.com/download",
    "faq": "https://circadianshield.com/faq",
    "blog": "https://circadianshield.com/blog/",
    "answerHub": "https://circadianshield.com/guides/best-blue-light-filter-software-2026/",
    "brandFacts": "https://circadianshield.com/brand-facts/",
    "brandFactsJson": "https://circadianshield.com/.well-known/brand-facts.json",
    "llmsTxt": "https://circadianshield.com/llms.txt",
    "sitemap": "https://circadianshield.com/sitemap.xml",
    "privacy": "https://circadianshield.com/privacy",
    "terms": "https://circadianshield.com/terms"
  },
  "lastUpdated": "2026-10-10",
  "macCompatibility": "Apple Silicon M1 through M4 Max; M5 has not been tested yet. Intel Macs also supported. macOS 14 or later."
}