utility

Signal Screen

Show large text, arrows, colors, and QR codes full-screen on a phone or computer.

Local processing

About your filesFiles and content selected in this tool are processed in your browser and are not uploaded to a Browser Kitty backend.

Operation demo See the basic workflow in a short video.

About this tool

Signal Screen turns a phone or computer display into a temporary large-format sign. Short messages automatically scale to fit the screen, and you can combine them with directional arrows and high-contrast background colors.

It can also generate QR codes locally from a URL or short text. It is designed for meetups, event guidance, travel, and other situations where you need to communicate something clearly from a distance.

Good for

Display a name or 'I'm here' at a station or airport so someone can spot you quickly
Use a large arrow to guide people at an event, reception desk, or temporary venue
Show a large QR code instead of reading out or typing a URL

What it can do

Key capabilities available in this tool.

Auto-fit large text
Large direction arrows
Local QR code generation
Fullscreen and wake lock

How to use

Choose whether to display text/arrows or a QR code.
Enter a message or select a quick preset or direction arrow. For QR mode, enter a URL or short text.
Adjust the background color or flashing pattern when needed. Flashing is disabled in QR mode to preserve scan reliability.
Select Fullscreen and position the device where it can be seen clearly.
On supported devices, Screen Wake Lock can help prevent the display from sleeping while the sign is shown.

Supported

Display: custom text, quick presets, and left/up/down/right direction arrows.
QR: generated locally from a URL or short text, with a current limit of 300 UTF-8 bytes.
Backgrounds: black, white, red, yellow, green, and blue, with automatic contrasting text color.
Display helpers: Fullscreen API, Screen Wake Lock where supported, and low-speed flashing patterns.

Limitations and notes

Flashing displays can cause discomfort or health effects for some people. Avoid using them around people who are sensitive to flashing light.
This tool is not a substitute for certified emergency signals, road signs, navigation signals, or aviation signals.
A web page cannot directly change the device's screen brightness; adjust brightness in the device settings when outdoors.
Fullscreen API and Screen Wake Lock availability depends on the browser and execution environment.

Frequently asked questions

Is my text or QR content sent to a server?

No. Text rendering and QR generation are processed in the browser, and Signal Screen does not send the entered content to a server at runtime.

Where is the QR code generated?

The QR generator is bundled into the HTML and creates the code locally on your device from the entered URL or text.

Can the display flash?

Yes. Slow, beacon, and SOS patterns are available, with a safety confirmation. Flashing is disabled when the device requests reduced motion.

Can the QR code flash too?

No. Flashing is automatically disabled in QR mode to prioritize reliable scanning.

Offline version and source code

The root-level signal-screen.html on GitHub is a standalone HTML file. Download it to use core text, arrow, and QR features locally without network access.

View source on GitHub