Frequently Asked Questions

Monitor Test Hub is a free, browser-based hardware diagnostic platform that provides professional-grade instruments for evaluating computer displays and touchscreen digitizers. It includes twelve specialized tools covering sub-pixel analysis, OLED uniformity, HDR luminance, color gamut profiling, multi-touch precision, and latency benchmarking. All tests execute entirely within your browser using WebGL, Canvas 2D, and Web APIs — no installation or account required. It is trusted by hardware reviewers, QA engineers, and display enthusiasts who need calibration-grade insight without proprietary software.

Yes, Monitor Test Hub is completely free to use with no paywalls, subscriptions, or hidden fees. Every diagnostic instrument in the suite is available to all users without registration. The project is open-source and community-driven, ensuring it remains accessible to everyone who needs professional display diagnostics.

No downloads, installations, or browser plugins are required to use Monitor Test Hub. All tools run natively in your browser using standard Web APIs including WebGL, Canvas 2D, the Pointer Events API, and performance.now(). Simply open the page and start testing immediately. Compatible with all modern evergreen browsers on desktop and mobile.

The Sub-Pixel Analyzer renders a series of WebGL GLSL ES 3.0 shader-driven test patterns that target individual red, green, and blue sub-pixels within each display pixel. By illuminating specific sub-pixel triplets at full and fractional intensities, it allows you to identify stuck sub-pixels, sub-pixel order (RGB, BGR, RGBW), and clarity rendering anomalies. The tool maps results to ISO 9241-307 pixel defect class categories (Class I–IV) for standardized defect classification. Testing is most effective at 1:1 native resolution with no browser zoom applied.

PPI (Pixels Per Inch) is a measure of pixel density — how many pixels are packed into each inch of a display panel. Higher PPI means sharper, more detailed imagery because individual pixels become too small to resolve with the naked eye at typical viewing distances. The commonly cited "retina threshold" of approximately 227 PPI at 12 inches viewing distance refers to Apple's definition, but the perceptual acuity limit varies by viewing distance and individual vision. Monitor Test Hub's PPI Calculator computes exact pixel density from your display's native resolution and panel size, helping you compare monitors and verify manufacturer specifications.

OLED burn-in (more precisely, permanent image retention) occurs when static UI elements — such as taskbars, HUD overlays, or navigation bars — are displayed at high brightness for extended periods. The organic compounds in OLED sub-pixels degrade at different rates depending on usage, causing those pixels to display differently even when showing new content. Modern OLED panels include pixel-shift, logo luminance limiting, and screen saver mitigations that significantly reduce risk. Monitor Test Hub's OLED Burn-In Risk tool evaluates your display's susceptibility using sustained static patterns and reports estimated long-term risk based on brightness level and exposure duration. Best practices include keeping brightness below 60%, enabling auto-brightness, and avoiding static overlays.

VRR (Variable Refresh Rate) allows a display to dynamically adjust its refresh rate in real-time to match the frame output of the connected GPU, eliminating screen tearing and reducing stutter without the input latency overhead of traditional V-Sync. It encompasses technologies such as AMD FreeSync, NVIDIA G-Sync, and VESA Adaptive-Sync. Monitor Test Hub's VRR Sync Engine generates a visual animation at a frame rate that ramps up and down across your display's supported VRR range, allowing you to visually verify VRR activation, identify the synchronization band, and spot any frame-pacing artifacts or flicker at the lower VRR threshold.

QD-OLED (Quantum Dot OLED) uses a blue OLED emitter layer combined with a quantum dot conversion film to produce red and green sub-pixels, resulting in extremely high color gamut coverage (typically >99% DCI-P3) and high peak brightness for a self-emissive display. WOLED (White OLED), used by LG in their consumer OLED panels, uses a white OLED stack with a color filter array to produce RGB output, offering excellent uniformity and deep blacks but generally lower peak brightness and slightly lower color gamut than QD-OLED. Both technologies exhibit pixel-level dimming and near-infinite contrast ratios, but differ in color volume, peak brightness, and sub-pixel structure, which Monitor Test Hub's Sub-Pixel Analyzer can help you characterize.

Monitor Test Hub's Color Gamut & ICC Profile tool measures the color primaries and white point of your display using a series of full-screen color patches rendered via the Canvas 2D API with a calibrated color management pipeline. After completing the measurement sequence, the tool generates an ICC v2-compatible profile file with a SHA-256 checksum computed via the Web Crypto API. You can then download the .icc file and install it through your operating system's display color management settings (macOS Color Profiles or Windows Color Management) to apply hardware-level color correction. Note that software-generated ICC profiles are supplementary calibration aids and do not replace hardware colorimeter measurements.

No. All processing in Monitor Test Hub happens 100% client-side within your browser. We operate zero telemetry servers and transmit zero diagnostic data to any external endpoint. Your display readings, touch coordinates, latency measurements, and ICC profile data never leave your device. The only data we persist locally is your theme preference in browser localStorage.

Monitor Test Hub works on all modern evergreen browsers including Chrome 100+, Firefox 100+, Safari 16+, and Edge 100+ on desktop and mobile. Tests using WebGL GLSL ES 3.0 require a browser with WebGL 2.0 support, which is available in all major browsers since 2022. Touch tests are optimized for mobile devices and trackpad-equipped laptops supporting the W3C Pointer Events API. Some advanced tests may perform best on high-refresh-rate displays.

Accuracy varies by test type and is subject to hardware-level limitations of the browser environment. Display tests that rely on pixel rendering (Sub-Pixel Analyzer, OLED Uniformity, Color Gamut) are highly accurate for relative comparisons but cannot replace hardware colorimeter or spectroradiometer measurements for absolute colorimetric calibration. Latency benchmarks using performance.now() achieve sub-millisecond resolution on most platforms but may be subject to timer resolution restrictions in some browsers for security reasons. Touch precision tests are accurate to the digitizer's native resolution. All results should be interpreted as engineering diagnostics rather than certified metrology measurements.

The Keyboard Tester Hub logs microsecond-level timestamp deltas between key release and subsequent keypress events using high-resolution performance.now() browser timers. If a re-trigger occurs below a 35ms threshold, it flags a switch chatter alert, indicating contact leaf bounce, spring fatigue, or oxidation in mechanical switches.

N-Key Rollover (NKRO) guarantees that every physical key pressed simultaneously on a keyboard will register independently without key dropouts or ghosting. 6KRO limits simultaneous reports to 6 keys. Membrane keyboards often suffer key blocking due to shared electrical traces, while mechanical keyboards use isolated diodes per switch to achieve true NKRO.