API Request Builder - Online Test REST Endpoints
Select HTTP method, set headers, and body. Send requests and see the full response. Lightweight Postman alternative.
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.
Select HTTP method, set headers, and body. Send requests and see the full response. Lightweight Postman alternative.
Register a oneβoff background sync and see it fire when connectivity returns. Debug service worker sync logic.
Register a periodic background sync and see the status. Schedule content updates for your PWA. API demo.
Pick a method, URL, headers, and body, then send an HTTP request directly from your browser. Debug APIs easily.
Find your public IP address and view approximate geolocation, ISP, and browser header details. No personal data stored. Static and instant.
Change the viewport meta tag and see how a page would render at different device widths. Understand responsive basics.
Measure your browser's GPU compute power using a simple WebGPU matrix multiplication. See raw FLOPS and compare with peers. Fully clientβside.
Test the experimental Translation API to translate text between languages directly in the browser, without cloud calls. Check support and copy the JavaScript starter.
Use the Magnetometer API to build a digital compass. See magnetic field strength and heading in real time.
Simulate adaptive bitrate logic by switching between different quality video segments. See how ABR algorithms work.
Drag a battery, resistor, LED onto a grid and simulate current flow. Show Ohm's law in action.
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.
Pomodoro timer with builtβin loβfi music playlist (synthetic). Focus and rest cycles. No copyright music; generated tones.
Process audio faster than realβtime with OfflineAudioContext. Apply filters and export the result. Dev tool.
Read the ambient atmospheric pressure in hPa using the Pressure Sensor API (if available). Realβtime graph.
Play a selection of local loβfi tracks (embedded). Simple UI with play/pause. No copyright issues. Stay focused.
Calculate correct aperture or distance for manual flash using the guide number formula. Input any two of GN, fβstop, or distance to find the third. Perfect for studio and event photographers.
Experiment with the experimental Prompt API and Summarization API right in your browser. See how the onβdevice AI model responds. Requires Chrome with AI features enabled.
Use your microphone to detect the dominant frequency of ambient sounds. Visualize the spectrum. Local Web Audio.
Play a simple monophonic synthesizer with your keyboard. Choose waveform, attack, decay, and filter. For music fun.
Register a periodic background sync to fetch fresh data even when the tab is closed. Understand the API and limits.
Connect an audio source to an Analyzer Node and display frequency and timeβdomain data. Learn Web Audio visualization.
Record daily systolic/diastolic readings and pulse. See a trend chart. All data saved locally in your browser.
Measure the integrated loudness of an audio file in LUFS and RMS. Check if your music meets streaming platform standards. Clientβside.
Shift the pitch of any audio clip by semitones without affecting playback speed. Perfect for music transposition. Local Web Audio.
Create experimental glitch noises by toggling virtual circuit bend points. No real electronics harmed. Fun noise toy.
Apply lowpass, highpass, and reverb to an audio source. See frequency response. Create your own guitar pedal. All local.
Apply a fisheye or barrel distortion to your photo with adjustable strength. Simulate extreme wide angle.
Record how many eggs your hens lay each day. Visual chart shows weekly trends, helping you spot drops in production that may signal health issues.
Zoom through the electromagnetic spectrum from radio waves to gamma rays. See wavelength, frequency, and applications. Static educational page.