UD5 Toolkit
Bluetooth Battery Monitor - Online Read Device Levels
Connect to a BLE device and read its Battery Service characteristic. See the charge level in a gauge.
Battery Status API Viewer - Online Check Level
Battery Status API Viewer
Instantly check your device's battery level, charging state, and estimated time remaining — directly in your browser.
Your browser does not support the Battery Status API. Please try using Chrome, Edge, Opera, or Samsung Internet.
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Frequently Asked Questions
The Battery Status API, also known as the Battery API, allows web browsers to access information about the system's battery charge level, charging state, and estimated time to fully charge or discharge. It helps web apps adapt their behavior based on power availability.
The Battery Status API is supported in Google Chrome, Microsoft Edge, Opera, and Samsung Internet. Unfortunately, Firefox and Safari have removed or never implemented this feature due to privacy concerns.
Yes. The API does not require any user permission, and the information it provides is very limited — only charge level, charging status, and estimated times. However, some browsers restrict or hide this API in insecure contexts (non-HTTPS) or for privacy reasons. This tool runs entirely in your browser; no data is sent anywhere.
The times are estimates reported by your operating system. They can fluctuate based on current system load, brightness, and running applications. If the value is "N/A" or "Calculating...", the OS cannot provide a reliable estimate at that moment.
No. The Battery Status API only exposes basic live metrics. Advanced diagnostics like battery health, cycle count, or temperature are not available through standard web APIs.
Updates are event-driven. The browser fires
levelchange events when the battery level changes, but the frequency depends on your operating system's reporting intervals — usually every few percent. You can leave this page open; it will reflect changes automatically.
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.
Resource Timing Viewer - Online See All Asset Loads
List all resources loaded by the current page and their detailed timing breakdown. In‑browser waterfall.
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.
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.
Service Worker Debugger - Online View States & Update
See the current Service Worker registration, its state, and scope. Send 'skipWaiting' and update. PWA debug.
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.
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.
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.
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.
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).
Reptile Shedding Logger – Online Track Stages & Humidity
Log shedding events, note duration, and track humidity to optimize next cycle. Healthy scales.
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.
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.
CSS Specificity Auditor - Online Sort & Find Overrides
Paste your CSS and see rules sorted by specificity. Find overrides and potential collisions. Understand your cascade.
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.
Renovate Bot Config Generator - Online Dependency Updates
Build a renovate.json file to automate dependency updates. Choose schedule, automerge, and package rules. Local.
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.
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.
Random Superpower Generator - Online Create Hero Abilities
Get a random, unique superpower with a detailed description and limit. Perfect for character creation or daydreaming.
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 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.
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.
HTML Input Type Playground - Online Test All Fields
See every HTML input type in one page. Check browser support and styling. Copy sample markup. Quick frontend reference.
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.
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.
Container Style Queries Playground - Online @container style()
Test the new style() function inside @container to query custom property values. Revolutionary component‑based responsive design.
Bayes' Theorem Calculator - Online Probability Update Tool
Easily compute posterior probabilities given prior, likelihood, and marginal likelihood. Visual diagram. All local.
CSS Typed OM Playground - Online attributeStyleMap Explorer
Manipulate CSS values as typed objects using attributeStyleMap. Convert between CSSUnitValue, CSSMathSum, etc. Futuristic CSS‑in‑JS.