Language Flashcard Randomizer - Online Vocabulary Trainer
Paste word pairs (or load pre-made sets) and practice with randomized flashcards. Flip to reveal translation, mark as known/unknown. Local data, no login.
UD5 Toolkit
Train your brain to read faster with Rapid Serial Visual Presentation
Paste word pairs (or load pre-made sets) and practice with randomized flashcards. Flip to reveal translation, mark as known/unknown. Local data, no login.
Create printable sight word flashcards from Dolch or Fry lists by grade level. Choose font size and card layout. Local only.
Load a GIF and adjust playback speed. Save modified GIF. Pure client-side processing.
Enter a URL and get a quick simulation of First Contentful Paint, LCP, and CLS using browser metrics. Lightweight alternative.
Paste a line of poem and see which syllable stresses create a particular meter. Educational tool.
Patch the PerformanceObserver and show your pageβs Core Web Vitals as you browse. See realβtime scores and suggestions.
Load an SRT file and shift all timestamps forward or backward by milliseconds or seconds. Fix out-of-sync subtitles instantly. Download corrected file.
Visualize how caffeine decays in your body over time. Enter intake amount and see remaining caffeine at bedtime to optimize sleep. Uses standard 5-hour half-life.
Check English spelling and get suggestions using the browser's built-in dictionary. Highlight errors instantly. No data leaves your machine.
Paste text and detect its language (70+ languages) using a simple character n-gram model implemented in JavaScript. No server communication.
Manually manage flashcards with 5 virtual Leitner boxes. See when to review each box next. All data local storage.
Click a letter and watch an animated stroke order for print or cursive. Good for kids learning to write.
Choose the right extinguisher for kitchen, electrical, or garage fires. Interactive class chart. Home safety education.
Enter a URL and extract tabβindex order violations and focusable elements. Quick accessibility audit. Clientβside fetch.
Generate customizable alphabet tracing sheets with uppercase and lowercase letters. Select letters to focus on. Instant print. Local only.
Load an animated GIF and adjust its frame delay to make it slower or faster. Download the modified GIF. All local.
Add book titles and authors to a toβread list. Move them to 'finished' and add a rating. Data saved locally.
Generate cryptographically secure BIP39 mnemonic phrases (12 or 24 words) for HD wallet seeds. All entropy generated locally.
Simulate reduced motion preference and test your animations. Copy the media query snippet. Keep your users safe.
Type a child's name and create a printable dotted trace sheet. Practice fine motor skills. Local only.
Enter Braille dot numbers (1β6) or paste Unicode Braille to decode into English text. Companion to textβtoβBraille.
Guided breathing exercises with animated circle for inhale/hold/exhale. Includes box breathing, 4-7-8, and resonant breathing patterns. Customizable intervals.
Apply dyslexiaβfriendly fonts, spacing, and background to any text. Preview and copy the formatted version. Improve readability.
Paste a website's HTML and see which text is only visible to screen readers (e.g., .srβonly). Preview the accessible layer.
See your current page load broken down into DNS, TLS, request, and DOM phases. Understand where time is spent.
See your current page load broken down into DNS, TLS, request, and DOM phases. Understand where time is spent.
Paste raw email headers and get a human-readable breakdown of the delivery route, authentication results, and delays. Private analysis.
Compare standard keyboard layouts side-by-side. Click keys to see characters. Useful for learning alternative layouts.
Simulate adaptive bitrate logic by switching between different quality video segments. See how ABR algorithms work.
Paste an ASCIIβarmored PGP message and view its packet structure. See the encrypted/plaintext blocks without decrypting.