World Flag Quiz - Online Guess the Country by Flag
Identify countries from their flags. Multiple difficulty levels and regions. Track your high score. Educational geography game. Works offline.
UD5 Toolkit
Discover detailed information about any country — instantly.
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Identify countries from their flags. Multiple difficulty levels and regions. Track your high score. Educational geography game. Works offline.
Interactive soprano recorder chart showing which holes to cover for each note. Switch between baroque and German fingering.
Click on a fold technique (spiral, crumple) and see a predicted color pattern. Print folding guide.
Enter a UPC or EAN barcode number and validate the check digit. See if it's a real product code. Local calculation.
Complete a series of visual pattern puzzles and get a fun estimated score. Purely for entertainment. No data collected.
Remove all EXIF, IPTC, and XMP metadata from your photos. Strip GPS location. Protect your privacy before upload.
Convert popular pet bird ages (budgie, cockatiel, macaw) to human years. Lifespan reference included. Fun educational tool.
Add Vietnamese diacritics to plain text by selecting tones. Remove them from text. For language learners.
Upload a logo to embed in the center of a QR code. High error correction so it still scans. Download PNG/SVG.
Create high-quality QR codes for URLs, text, Wi-Fi, and contact info. Customize colors and size. Download as PNG/SVG. No data leaves your device.
Eliminate duplicate lines from text instantly. Keep only unique lines or see which lines were removed. Handy for cleaning email lists and raw data.
Create QR codes with custom colors, gradients, and an embedded logo. Download as high-quality PNG/SVG. Fully local generation.
Generate a QR code with a custom icon or logo in the center. Choose error correction level. Download as high‑res PNG.
Convert illuminance units: lux, foot-candle, phot. Useful for lighting design and photography. Quick and free.
Paste rich text and clean it to plain text. Normalize line endings and whitespace. Prepare for code or databases.
Press any key to see the complete KeyboardEvent properties: key, code, keyCode, modifiers. Indispensable for game & shortcut developers.
Load an audio file and visually trim it by dragging handles on the waveform. Export the trimmed clip. All local.
Encrypt and decrypt messages using the classic Caesar cipher with configurable shift key. Fun for puzzles and basic cryptography lessons. Entirely browser-based.
Generate a pop signal to determine if speakers are wired in phase. Quick stereo test.
Easily apply ROT13 cipher to obfuscate or reveal text. A classic letter substitution cipher that works bidirectionally. Purely client-side processing.
Generate a self‑signed X.509 certificate and private key for local development. All created in your browser. No server involved.
Select meat type and enter weight to get recommended cooking time and temp. Built-in timer with alarm.
Apply a classic Caesar shift cipher with any key. Encrypt or decrypt text instantly. Brute force option included.
Set a meditation session with singing bowl sounds at start, interval chimes, and end bell. No ads, pure serenity.
Automatically adjust brightness, contrast, and saturation of a photo. Click to enhance and download. Canvas‑based.
Convert any text to proper sentence case. Capitalize the first letter after every period, question mark, or exclamation.
Interactive scale showing dB levels of everyday sounds with playable samples. Hearing safety.
Searchable list of Q-codes with meanings. Also includes RST system. Prepare for license.
Offline‑first search of the CanIUse database. Type a CSS property, HTML element, or API and see global support percentages. Fast.
Browse the built‑in styles that browsers apply to HTML elements. Understand why your page looks different. Static reference.