Connection Speed Estimator - Online Download Test
Quickly estimate your internet connection speed by downloading a small test file. See class and recommendations.
UD5 Toolkit
Measure your internet connection's download speed, upload speed, and latency — directly from your browser.
Quickly estimate your internet connection speed by downloading a small test file. See class and recommendations.
Enter a URL and get a rough client-side performance simulation: request count, DOM size, and potential speed tips. No real Lighthouse.
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
Paste text to calculate the estimated reading time based on your WPM. Set speaking time too. Perfect for speeches.
Check if a website is globally reachable or experiencing issues. Status code and latency displayed. Quick browser-side test.
Test the Web Share API by sharing text, links, and files directly from the browser. Check compatibility and see example code.
Enter a URL and get a one‑page report of titles, description, headings, image alts, and broken links. All from browser.
Compare font‑display values (block, swap, fallback, optional) on the fly. See how text renders during web font load. Choose the right strategy.
Simulate a PWA receiving shared text, links, and images. Test the Web Share Target API without a server.
Enter a URL and see its favicon at all standard sizes. Check if it's properly defined. SEO basic check.
Inject dynamic messages into ARIA live regions and monitor how they trigger screen reader announcements. Debug a11y.
Paste a Content‑Security‑Policy header and get a human‑readable breakdown. See potential risks and suggestions.
Morse characters flash on screen; you must tap them correctly on a single button. Points for accuracy and speed. Learn Morse in a fun way.
Enter hole saw diameter and material to find the recommended RPM and feed pressure. Prevent burning and kickback.
Enter a URL and fetch its text/background colors to perform a bulk contrast check. See warnings for WCAG violations.
Compare text‑rendering: auto, optimizeSpeed, optimizeLegibility, geometricPrecision. See kerning and ligature changes live.
Check if the current page can be loaded offline by examining the service worker cache. Developer tool for PWAs.
Set launch angle, initial speed, and height. See the trajectory, max height, and range plotted on a canvas. Learn kinematics.
Test the Content Indexing API to add a page to the device's content feed. See how your PWA integrates with the OS.
Drag a slider to compare your original image with a compressed version (e.g., WebP). See the quality difference and file size savings.
Convert fuel economy units between miles per gallon (US/UK), liters per 100 km, and kilometers per liter. Useful for international car comparisons.
Upload an image containing a QR code and decode its content. Works offline using JavaScript QR decoder. No camera needed.
Paste two texts, compute the diff, and render the result as a highlighted image. Easier to share changes visually.
Tap any key multiple times. Shows average BPM, standard deviation, and a visual metronome beat. More accurate than simple tap.
A beautiful full‑screen binary clock showing hours, minutes, seconds in glowing bits. Dark mode perfect for desks.
Extract plain text from a PDF file entirely in the browser using PDF.js. No file upload to server. Supports multi-page extraction and search.
Analyze text for keyword frequency and density. Highlights over-optimized terms. Perfect for content writers and SEO editors. Entirely browser-based.
Paste text with mixed Arabic/Hebrew and English. See the Unicode bidi class of each character and ordering. i18n debugger.
Enter a URL and extract the font stacks and web font URLs used on that page. Quick typography research.
Watch for updates to aria‑live regions and log what a screen reader would announce. Debug live regions.