Flashcard Review Timer - Online Leitner Box Spaced Repetition
Manually manage flashcards with 5 virtual Leitner boxes. See when to review each box next. All data local storage.
UD5 Toolkit
Perfect Soft, Medium & Hard Boiled Eggs — Every Time
Manually manage flashcards with 5 virtual Leitner boxes. See when to review each box next. All data local storage.
Convert a recipe from oven or stovetop to slow cooker (high/low) and vice versa. Perfect doneness.
Enter a URL and get a quick simulation of First Contentful Paint, LCP, and CLS using browser metrics. Lightweight alternative.
Turn a cardinal number (23) into its ordinal form (23rd). Supports large numbers. Simple and quick.
Adjust page characteristics (image size, server delay, layout shift) and see the simulated Core Web Vitals scores. Understand what impacts performance.
Instantly convert 12‑hour AM/PM time to 24‑hour format and vice versa. Simple and essential for travelers.
Patch the PerformanceObserver and show your page’s Core Web Vitals as you browse. See real‑time scores and suggestions.
Generate cryptographically secure BIP39 mnemonic phrases (12 or 24 words) for HD wallet seeds. All entropy generated locally.
Assign a color and number to each room and generate a printable inventory sheet. Check off box contents as you pack. Stay organized.
Play any video at 0.25x to 4x speed. Save the modified speed as a new file. Perfect for analysis or fun.
Play any video at a custom rate (0.25x to 4x) without audio pitch change. Save the playback speed as a link. Local.
Compare time across multiple time zones and find a suitable meeting time. Convert a specific time to various cities. Browser-based and always accurate.
Deep-dive into text with detailed character and letter frequency analysis. Supports multiple languages and includes whitespace control. Fast and private.
Create a temporary chat room between two browser tabs or devices on the same network using WebRTC data channels. Copy the code.
Load an SRT file and shift all timestamps forward or backward by milliseconds or seconds. Fix out-of-sync subtitles instantly. Download corrected file.
Click to see a random dog breed with key facts (size, energy, lifespan). Built-in breed database. Fun way to explore dog breeds. Local only.
Create cards and review using a spaced repetition algorithm (Leitner box simulation). Cards stored locally. Improve exam prep.
Create glowing, neon‑style text effects with multiple text‑shadows. Adjust colors and intensity. Copy the CSS.
Load an animated GIF and adjust its frame delay to make it slower or faster. Download the modified GIF. All local.
Drag songs into a setlist and see total duration. Perfect for planning a concert or DJ set.
Build your own Connections‑style puzzle with 4 categories and 4 words each. Share the puzzle as a code or link.
Open the same page in two tabs and send messages between them. See real‑time cross‑tab communication. Learn the API.
Create or solve logic grid puzzles (like Einstein's riddle). Enter clues and mark the grid. Practice logical deduction. Local only.
Generate customizable alphabet tracing sheets with uppercase and lowercase letters. Select letters to focus on. Instant print. Local only.
Load a GIF and adjust playback speed. Save modified GIF. Pure client-side processing.
Choose tabular‑nums, diagonal‑fractions, ordinal and see the effect on a numeric list. Elegant data presentation.
Fill in a pre‑designed meeting notes template and copy as formatted HTML or plain text. Quick documentation.
Watch classic sorting algorithms step through a randomized bar chart. Adjust speed and array size. Great for learning algorithm efficiency.
Play Rock Paper Scissors against a smart random CPU with win/loss/draw tracking. Smooth CSS animations. No ads, pure fun.
Test your knowledge of American Sign Language letters. See a sign and type the letter. Improve receptive skills. Local.