Speaker Polarity Test β Online Click & Listen
Generate a pop signal to determine if speakers are wired in phase. Quick stereo test.
UD5 Toolkit
navigator.geolocation Response
GeolocationPosition
GeolocationPosition object that the browser's navigator.geolocation.getCurrentPosition() API would return. This is extremely useful for debugging region-specific content, map integrations, store locators, and any feature that depends on the user's physical location.
about:config in the address bar, search for geo.provider.network.url, and modify it to return custom coordinates. Alternatively, use the Location Guard extension.accuracy property in a GeolocationCoordinates object represents the radius of uncertainty around the reported position, measured in meters. A lower value means higher confidence. GPS typically provides accuracy between 3β30 meters, while IP-based geolocation may have accuracy of hundreds or thousands of meters. When simulating, you can set this to any realistic value to test how your app handles varying precision levels.
GeolocationCoordinates object includes optional properties: altitude (height above sea level in meters), altitudeAccuracy (uncertainty of the altitude), heading (direction of travel in degrees, 0β360), and speed (velocity in meters per second). This tool lets you set altitude and altitude accuracy. For full motion simulation (heading + speed), Chrome's Sensors panel supports those as well.
navigator.geolocation output. To truly override your browser's location, use the Chrome DevTools Sensors panel as described above, or install a browser extension designed for location spoofing. This tool helps you prepare the exact coordinates and preview the data before applying the override.
Generate a pop signal to determine if speakers are wired in phase. Quick stereo test.
Display striped patterns that can cause visual distortion. Learn about visual stress. Switch colors.
Display an astigmatism dial and instructions for self-assessment. Educational, not a medical diagnosis.
Hear a word spoken by browser TTS and type the spelling. Choose difficulty or paste your own list. Great for kids. Local only.
Send HEAD requests to popular websites and measure the roundβtrip time. Quick network health check. Clientβside.
Hear text spoken word by word with boundary events. See the exact index and character. Advanced TTS dev tool.
Load a video and visually check if audio aligns with lips. Use frameβbyβframe stepping. Debug playback issues.
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
Check if your page triggers the beforeinstallprompt event. Simulate the install flow. Debug PWA installability.
Measure your visual and auditory reaction speed. Average and best times shown. No data collected. Pure Javascript timing.
Paste your AcceptβLanguage header and see which languages your site should serve based on quality values. Internationalization helper.
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
Override your browser's geolocation to any coordinates and test how your app responds. For development and privacy testing.
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Test the Fullscreen API: request fullscreen on a colored div, detect changes, and copy the JavaScript boilerplate.
Test the Web Share API by sharing text, links, and files directly from the browser. Check compatibility and see example code.
Check if your browser and display support the wider DCIβP3 color space. See the difference with a simple test pattern.
Enter any phrase and instantly see if it's a palindrome, ignoring spaces and punctuation. Fun for word nerds.
Paste a set of hex colors and simulate how they appear with common color vision deficiencies. Get contrast warnings.
Generate random, formatted ID numbers that match pattern rules for various countries. For testing input validation. No real data.
Pick a method, URL, headers, and body, then send an HTTP request directly from your browser. Debug APIs easily.
Quickly test if your webcam, microphone, and speakers work correctly. See live video and audio meter. No data sent.
Generate random but realisticβlooking data arrays (users, products, orders) with typos and missing fields. For test robustness.
Simple interactive eye dominance test: hold up a virtual dot and see which eye stays aligned. Educational.
Build an iframe with different sandbox flags and see live which features are blocked. For secure embedding.
Simulate random mouse moves, clicks, or keystrokes to test idleβtimeout logic. Stops when you move the mouse. Dev test.
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
Play leftβonly, rightβonly, and frequency sweeps to test your speakers or headphones. Quick audio check.
See a live VU meter of your microphone's input level. Test if your mic is working and adjust gain. Privacyβfriendly.
Generate valid, random unicast MAC addresses for testing or spoofing. Select OUI prefix if desired. Local only.