Use guide

Phone white screen light — softbox & reading lamp

Turn a phone browser into a bright soft light for reading, close work, or walking a dark room — no extra app.

Steps

Open Instant White in the phone browser.
Tap Open this preset (Max white) or raise brightness to 100% in controls.
Tap the page if you want fullscreen; enable Wake so the screen tries to stay on.
Raise system brightness for maximum output. Point the screen at the subject, not into anyone’s eyes.

Warm white is usually better for bedside reading than pure white: /?preset=night&f=1&w=1
For product photos, bounce the screen off a wall if the light is too hard.
Max white deep link: /?c=white&b=100&f=1&w=1

A phone panel is a small, battery-powered lamp. It will heat up and drain charge at max brightness.
The f=1 query asks the page to enter fullscreen. Browsers typically allow Fullscreen API only after a user gesture (tap or click). The request can be denied, and iOS Safari often ignores programmatic fullscreen.
The w=1 query asks for the Screen Wake Lock API so the display stays on. It requires a visible document, usually HTTPS, and is missing or unreliable in some browsers (notably many iOS Safari versions). The screen can still sleep if the OS, battery saver, or the browser refuses the lock.
Do not use it as a driving headlight or to stare at for long periods.

Part of Instant White — free fullscreen white screen & solid color light tool.