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Blue Light Filter

Warm-tone overlay for late-night reading.

Press F for fullscreen
Controls
Warmth60%

About Blue Light Filter

Adds a warm amber overlay over a deep-brown base, so any window placed in front of it inherits a warm tint. Use it as a poor-man's f.lux when your OS doesn't have a night-light setting, or place it behind a translucent reading app for a sepia look. The Warmth slider controls overlay strength from 0% (deep brown alone) to 100% (a pronounced amber wash).

Night Reading and Bedtime Wind-Down

Open the blue light filter fullscreen before bed and the warm amber overlay reduces the harsh blue tones that interfere with melatonin production. While a web page cannot change your panel's actual spectral output, the warm tint makes late-night reading more comfortable and signals your brain that it is approaching sleep time. Use it on a tablet for bedtime e-book reading, on a laptop for late-night browsing, or on a bedside monitor as a soft nightlight. The warmth slider lets you dial the intensity from a subtle sepia to a pronounced amber, matching your personal comfort preference.

Late-Night Work Session Eye Comfort

Remote workers, students, and developers who work past midnight use the warm overlay to reduce eye strain during long sessions. The amber tint decreases the perceived brightness of white text on dark backgrounds, making code editors and documents more comfortable to read in dark rooms. While this tool does not replace OS-level night mode or dedicated blue-light glasses, it provides an instant warm overlay on any device without installation. Pair it with your operating system's dark mode for a complete low-strain night-work environment.

Ambient Warm Lighting Alternative

Place a tablet or secondary monitor running the blue light filter in your living space as a warm ambient light source. The soft amber glow creates a cozy evening atmosphere without the blue-rich light that disrupts circadian rhythms. Use it during evening relaxation, meditation, or family time. Parents run it on a tablet in children's rooms as a warm nightlight that is gentler than standard white night lights. The adjustable warmth slider lets you find the exact tone that works for your space, from barely-warm to deep amber.

How to use it

  1. 01

    Press F for fullscreen

    The warm field fills the panel.

  2. 02

    Dial Warmth

    Drag the slider in the controls panel. 30-40% reads natural; 70%+ is a strong night-light effect.

  3. 03

    Use it as a backdrop

    Tile any other app over this page in fullscreen and the warm field bleeds through their transparent regions.

  4. 04

    Download the current view as a PNG

    Click the download icon in the top-right toolbar — it sits between the settings gear and the fullscreen button. We detect your display's physical pixel count (screen resolution × device pixel ratio) and rasterize the current configuration into a Retina-sharp PNG. The file lands in your browser's default downloads folder; to save straight to the Desktop, enable 'Ask where to save each file' in your browser settings. The filename includes the resolution so you can keep multiple variants side by side.

Frequently asked

The shortest path between you and the answer.

Does this actually filter blue light?

No. A web page can only paint colors; it cannot change the panel's spectral output. A real blue-light filter requires an OS night-mode or a hardware-level color profile. This page is a visual approximation, useful for ambient tinting but not a medical claim.

Is this tool free?

Yes. Every ScreenTools.co tool is free, with no account, no paywall, and no install.

Does it work on mobile?

Yes. Layouts adapt to phone and tablet screens. Mobile Safari restricts true fullscreen, but the page fills the viewport and you can add the page to your Home Screen for an app-like experience.

Does it work offline?

Once a tool's page has loaded once, the runtime is local. A few tools that fetch fonts or icons need the first hit online; after that, refresh works offline.

Does this collect my data?

No personal data leaves your browser. The site has lightweight, privacy-respecting analytics for aggregate counts (which tool was opened) and nothing else.

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