UD5 Toolkit
Battery Status API Viewer - Online Check Level
See your device's battery level, charging status, and discharge time using the Battery Status API. Fun utility.
Bluetooth Battery Monitor - Online Read Device Levels
Bluetooth Battery Monitor
Check battery levels of your Bluetooth devices instantly – no app, no setup. Works directly in your browser using Web Bluetooth.
No devices connected
Click "Scan for Devices" to find nearby Bluetooth accessories with battery service.
Scanning...
Looking for Bluetooth devices...
Frequently Asked Questions
This tool uses the Web Bluetooth API to detect nearby Bluetooth Low Energy devices that advertise the standard Battery Service (UUID 0x180F). Once connected, it reads the Battery Level characteristic (0x2A19) and displays the percentage. It can also listen for battery changes in real time. Everything runs locally in your browser – no server, no tracking.
Any Bluetooth device that follows the standard Battery Service specification. This includes many wireless headphones (Sony, Bose, JBL), fitness bands, smartwatches, mice, keyboards, game controllers, and even some smart home sensors. Note: the device must be BLE‑enabled and currently advertising the service.
Make sure Bluetooth is turned on (computer and device), put the device in pairing/discoverable mode, then click "Scan for Devices". A browser pop‑up will list available devices. Choose your device and accept the connection request. The battery level appears instantly.
Yes, on Android devices using Chrome or other Chromium‑based browsers. Web Bluetooth is not yet supported in Safari on iOS, but you can use the Bluefy or WebBLE apps to enable it. Desktop Chrome, Edge, Opera, and Samsung Internet all work.
Absolutely. The connection is established entirely inside your browser. No battery data or device identifiers are ever sent to our servers. The tool does not use cookies, analytics, or any form of tracking. You stay in full control.
First, ensure Bluetooth is enabled and the device is awake and in range. Some devices need to be unpaired from the system before they appear in the browser chooser. If the device does not implement Battery Service (0x180F), it won't be listed. Try refreshing the page and scanning again.
Yes! After connecting one device, click "Scan for Devices" again to add another. Each device has its own card with a live battery gauge and a disconnect button. Practical limits depend on your Bluetooth adapter and browser.
Defined by the Bluetooth SIG, the Battery Service (0x180F) exposes the Battery Level characteristic (0x2A19) that reports charge as a percentage (0–100). Some manufacturers also include a Battery Power State, but this tool focuses on the simple level readout that almost all BLE devices support.
Battery Life Calculator - Online Device Runtime Estimator
Estimate how long a battery will last given capacity (mAh/Wh) and load current. Also computes backup time for power banks. Quick and local.
Battery Saver Dark Screen - Online Minimal Power Page
A completely black page to save battery on OLED devices. Click to go fullscreen. Simple utility.
Guest Wi‑Fi Login Card – Online Printable Access Page
Enter network name and password to generate a stylish printable card for visitors. Local, no data leak.
Paint Timing API Monitor - Online FP, FCP & LCP
Access the Paint Timing API and display First Paint, First Contentful Paint, and Largest Contentful Paint times. Quick perf check.
Resource Timing Viewer - Online See All Asset Loads
List all resources loaded by the current page and their detailed timing breakdown. In‑browser waterfall.
Sunset Alarm – Online Snooze Based on Tonight's Sunset Time
Set an alarm relative to today's sunset (e.g., 30 minutes before). Perfect for evening routines. Uses geolocation (optional).
Road Trip ETA Calculator - Online Arrival Time with Stops
Estimate arrival time with driving duration, breaks, and time zone changes. Plan your road trip precisely.
Service Worker Debugger - Online View States & Update
See the current Service Worker registration, its state, and scope. Send 'skipWaiting' and update. PWA debug.
Reptile Shedding Logger – Online Track Stages & Humidity
Log shedding events, note duration, and track humidity to optimize next cycle. Healthy scales.
Web Server Log Parser - Online Apache/Nginx Analyzer
Paste a raw server log snippet and see a structured table with IP, method, URL, and status. Quick audit.
Service Worker Lifecycle Viewer - Online Debug Tool
See the current state of a Service Worker for your page: installing, waiting, active. Unregister or skip waiting. Developer utility.
Dark Mode Toggle Demo - Online Respect System Preference
Implement a dark/light theme toggle that respects prefers‑color‑scheme. Copy the complete JavaScript and CSS.
CSS Blend Mode Playground – Online background-blend-mode & mix-blend-mode
Load images or use colors and apply all 15 CSS blend modes. Visual tester for creative effects.
Promise State Viewer - Online Check Resolve & Reject
Create promises that resolve or reject after a delay. See state changes and chain .then/.catch. Debug async code.
Prioritized Task Scheduler Demo - Online scheduler.postTask()
Schedule tasks with user‑visible, user‑blocking, or background priority. See execution order and delays. Modern web perf.
Logical Properties Playground - Online RTL & Writing Mode
Swap between physical and logical properties (margin‑inline vs margin‑left). Live preview with writing‑mode. Internationalize your CSS.
Webpage to PDF Printer - Online Save as Document
Enter a URL and instantly generate a PDF version using the browser's print-to-pdf engine. Private, no upload.
CSS Specificity Auditor - Online Sort & Find Overrides
Paste your CSS and see rules sorted by specificity. Find overrides and potential collisions. Understand your cascade.
Random Superpower Generator - Online Create Hero Abilities
Get a random, unique superpower with a detailed description and limit. Perfect for character creation or daydreaming.
Color Scheme from Image - Online Extract Palette
Upload any picture and instantly get a 5‑color palette. Useful for UI design themes. Canvas‑based extraction.
CSS Custom Properties Collector - Online List All :root Vars
Paste your CSS and get a sorted list of all custom properties defined under :root with their values. Quick audit.
will‑change Property Visualizer - Online GPU Hint Tool
Apply will‑change to any element and see its effect on compositing. Learn best practices for smooth animations.
Renovate Bot Config Generator - Online Dependency Updates
Build a renovate.json file to automate dependency updates. Choose schedule, automerge, and package rules. Local.
Webpage to PDF - Online Print & Save as Document
Enter a URL and instantly generate a PDF version using the browser's print-to-pdf engine. Private, no upload.
user‑select CSS Playground - Online Text Selection Control
Apply user‑select: none, text, all and see how it affects selection. Copy the CSS snippet for your UI elements.
Sourdough Hydration Calculator - Online Bread Baker's Tool
Calculate flour, water, starter amounts to achieve a target loaf hydration. Adjusts for starter hydration. Instant local calculation.
Vite Config Generator - Online vite.config.js Builder
Build a Vite configuration file by selecting plugins (Vue, React, etc.), aliases, and build options. Copy the final code.
Container Style Queries Playground - Online @container style()
Test the new style() function inside @container to query custom property values. Revolutionary component‑based responsive design.
@property Registration - Online Custom CSS Property Animator
Register a custom CSS property with syntax, initial value, and inherits. Animate colors and numbers that couldn’t before.