Initializing, please wait a moment

LCD test

An LCD test runs full-screen solid colours - red, green, blue, white, and black - so backlight bleed, stuck pixels, and uneven illumination show against a uniform field within a few seconds. Open the tool, tap each colour swatch to fill the entire screen, and look for any dot, line, or patch that does not match the surrounding colour.

Often called a screen test or display test, this LCD check is the same quick diagnostic: show one solid colour at a time so dead or stuck pixels and backlight bleed stand out against a uniform background.

Three steps to run an LCD test: open the tool, fill the screen with each solid colour, then look for stuck pixels or backlight bleed.
Three steps: open the LCD test, fill the screen with each solid colour, then look for stuck pixels or backlight bleed.
PropertyValue
FormatOnline tool, no install
SpeedBrowser-side; full-screen colour cycle in seconds
PrivacyRuns locally in the browser - no upload
Implementing toolhttps://freetoolonline.com/device-test-tools/lcd-test.html
Colours tested5 solid screens - red, green, blue, white, and black
Stuck pixel types3 types: dead (always off), stuck (always on), hot (fixed colour)

Reviewed by the Free Tool Online editorial team · Tested in the current versions of Chrome, Firefox, Safari, and Edge before publishing. No account is needed to use any tool. Report a bug - we triage within 72 hours. · Last refreshed April 2026.

Why trust these tools

  • Ten-plus years of web tooling. The freetoolonline editorial team has shipped browser-based utilities since 2015. The goal has never changed: get you to a working output fast, without an install.
  • No install, no sign-up. Open a tool and get a working output in seconds - nothing to download and no account to create. Tools that need heavy processing run it on our service, so even a low-powered machine gets the job done.
  • Analytics stops at the page view. We measure which pages get visited, not what you type or upload inside a tool. There is nothing to sign in to and no profile is attached to your input.
  • Open-source core components. The processing engines underneath (libheif, libde265, pdf-lib, terser, clean-css, ffmpeg.wasm, and others) are public and audit-able. We link to each one in its tool page's footer.
  • Free, with or without ads. All tools are fully functional without sign-up. The Disable Ads button in the header is always available if you need a distraction-free run.

Related tools:

  • Camera Test - Free camera test online: live preview, resolution readout, switch front and back camera, capture
  • Keyboard Test - Keyboard test online - press each key to highlight it, spot non-working keys, and verify Num Lock,
  • LCD Test - Test your LCD screen for dead pixels, stuck pixels, and backlight bleed.
  • Microphone Test - Free microphone test online: live spectrum meter, mic permission check, and optional speaker
  • Device Test Tools - Test camera, microphone, keyboard, and LCD online before meetings.
  • All Guides - Browser Tool Library - Free, in-browser guides on compressing files, converting HEIC, testing screens, hashing, PDFs, and
  • Screen Recorder - Record your screen, camera, or microphone in the browser, blur faces while recording, and download
  • GPU Test - WebGL Benchmark & Info - GPU Test - WebGL Benchmark & Info - See what your browser's graphics stack can do - WebGL 1 and 2

Tags: #guide, #device-test, #lcd, #lcd-test, #screen-test, #dead-pixel

Related guides:

What users say about this tool

A super fast tool to verify dead pixels on any monitor or screen, including tablets and mobile devices. I use it often without errors.
Jonatan Y. (MX) via Trustpilot

Read more reviews on Trustpilot or Buy Me a Coffee.

Loading reviews...