Pick a light
Choose one of eight kinds: a ring light, the full screen, a bulb, a spotlight, an edge light, two side lights, a tube light or a candle. The picture above changes at once.
Make your screen glow like a ring light, a bulb or a night lamp: eight kinds of light with an on and off switch, brightness, and colour from cool daylight (6,500 K) to a golden night bulb (2,700 K), with nothing uploaded.
The light is showing full screen.
A glowing ring, like the ring lights used for video calls and selfies.
The light stays on until you switch it off.
This browser cannot keep the screen awake from a web page. Set a longer screen timeout in your device's settings.
A web page cannot raise your screen's own brightness: for the most light, turn your device's brightness up and open the full screen view. The colours are worked out for a standard screen; a night light or blue light filter setting on your device changes them. Nothing is uploaded and the camera is never used.
Choose one of eight kinds: a ring light, the full screen, a bulb, a spotlight, an edge light, two side lights, a tube light or a candle. The picture above changes at once.
The Light switch above the picture turns the light on and off, like the switch on a wall. Your settings stay as they are while it is off.
Slide from 2,700 K, the golden glow of a night bulb, to 6,500 K, a cool daylight white, or tap a ready-made light such as Warm white or Studio daylight. Eight colour lights sit below.
Dim the light from 100% down to 1%. The colour stays the same as it dims. A second slider makes the ring thicker, the bulb bigger or the panels wider.
Press Full screen and the light fills the whole screen. Move the mouse or tap to bring back the small bar with the switch, the brightness buttons and Exit.
Let the light switch itself off after 5 minutes to 2 hours, handy for a night light. Keep the screen awake stops your device from dimming the screen while the light is on.
A ring for video calls, a full white screen for the most light, a soft bulb, a frame that leaves the middle of the screen free, and a candle for a quiet evening.
Each setting from 2,700 K to 6,500 K is worked out from the science of light, not picked by eye. Measured back on a standard screen, every setting is within half a percent of its number.
Red, green and blue are dimmed together in the right proportion, so a golden light keeps its tint as it dims instead of drifting towards grey or red.
Pick the golden night bulb, turn the brightness down and set the timer. The light switches itself off, and the page lets the screen sleep again.
There is no account and no upload, and the camera and microphone are never asked for. Only your last settings are kept, in this browser on this device.
It works on any screen. A second monitor or a tablet beside your laptop makes a handy extra light for a video call.
White light comes in many tints. Heat a piece of metal and it glows red, then orange, then yellow-white, then bluish white: the tint is named by that temperature in kelvin (K). So a low number is a warm light and a high number is a cool one. Bulbs for homes are often sold as 2,700 K to 3,000 K (warm white), about 4,000 K (neutral white) and 5,000 K to 6,500 K (daylight). Studio lights are often 3,200 K or 5,600 K.
A screen is made to be looked at, not to light a room, so it gives much less light than a ceiling bulb or a real ring light. It is still useful close up: as a soft light on your face for a video call in a dim room, as a glow to read a label by, or as a night light. A web page cannot raise the screen's own brightness, so set that to full on your device first. The bigger the lit area, the more light: Full screen gives the most.
The colours are worked out for a standard screen, whose own white is a daylight white of about 6,500 K. Screens differ a little from that. A night light, blue light filter or automatic colour setting on your device also tints everything the screen shows: switch it off while you use the light if you want the colour as numbered. Many people find a dim, warm light more comfortable late in the evening.
No. A web page can only choose the colours it shows. The brightness slider here dims the light inside the page; it cannot raise your screen above its own brightness setting. For the most light, turn your device's brightness all the way up, choose Full screen light at 6,500 K and 100%, and open the full screen view.
K stands for kelvin, the unit of colour temperature. Low numbers are warm: 2,700 K is the golden light of a night bulb. High numbers are cool: 6,500 K is a crisp daylight white. Bulb boxes carry the same numbers, so you can match the light on your screen to the bulbs in your room.
The white of a standard screen is itself a daylight white of about 6,500 K. So at 6,500 K the tool shows the screen's own white, which is also the brightest light a screen can give. Every warmer setting is made by holding back some green and more blue.
With Keep the screen awake switched on, the page asks your device not to dim or lock the screen while the light is on and the page is in view. Most current browsers allow this; a battery saver mode can refuse it. If your browser does not offer it, the switch is not shown: set a longer screen timeout in your device's settings instead.
No. The tool never asks for the camera or the microphone and nothing is uploaded. It only colours your own screen. Your last settings (light type, colour, brightness and size) are kept in this browser on this device so the light looks the same next time.
No. A screen gives much less light than a lamp made for the job. It works as a soft fill light for a face at arm's length in a dim room, as a night light or as a reading glow. For a bright room or a subject further away, a real ring light or a lamp does better.
No light here flashes or strobes. The candle flickers gently: the flame loses at most 12% of its light and changes fewer than three times a second. If your device is set to reduce motion, the candle burns steadily.