Color Harmony Chooser - Online Complementary & Triadic
Find complementary, triadic, analogous, and split-complementary color combinations. Interactive color wheel. Essential for UI design.
UD5 Toolkit
Generate lighter tints and darker shades from any color. Click to copy HEX codes instantly.
Find complementary, triadic, analogous, and split-complementary color combinations. Interactive color wheel. Essential for UI design.
Select parent colors and genotypes to predict possible offspring coat colors. Based on simple Mendelian genetics for common breeds.
Generate a camping checklist based on trip style (car, backpacking, glamping). Check off items. Fully local.
Select a heading font and see a set of well‑paired body fonts. Live preview with your own text. Copy the import code.
Instantly generate random UUIDs (version 4) for use as unique identifiers in software development. No registration, completely free and private.
Enter adjusted gross score, course rating, and slope to calculate the round's handicap differential. Track your index.
Take a perfectly fine phrase and insert realistic-looking typos. For pranks or testing spell‑checkers.
Calculate absolute error, relative error, and percent error between experimental and theoretical values. For science students. Instant local math.
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
Enter notes or chords on a virtual fretboard and generate ASCII tablature. Quick way to share musical ideas.
Convert any text into its binary representation (8-bit per character). See the raw bits. Suitable for learning computer fundamentals. All local.
Paste HTML and detect unclosed tags, invalid nesting, and duplicate IDs. Lightweight client‑side validation.
Enter recent scores, course rating, and slope to estimate a golf handicap index. Simple formula for unofficial tracking. Local only.
Paste HTML snippet and see calculated tab order. Identify missing focusable elements. A11y helper.
Generate random Scattergories‑style lists with a random letter and 12 categories. Great for online game night.
Validate YAML syntax with line‑by‑line error messages. Also format messy YAML into clean, indented output. All in your browser.
Enter your weight, height, boot sole length, and skier type to see the recommended DIN release setting.
Paste your sitemap XML and check for missing namespaces, invalid URLs, or size limit violations. Keep your SEO healthy.
Turn any sentence into mocking SpongeBob‑style text. Choose intensity. Copy and paste into chats. Pure client.
Enter products with different prices and weights/volumes. The tool ranks them by best value per unit. Save money effortlessly.
Generate a comprehensive first aid kit list for home, car, or hiking. Check off what you have.
Two players type the same text on the same keyboard (WASD vs Arrow zones) and race to finish first. Fun classroom game.
Compute the error function and complementary error function for any real x. Quick and precise. Pure frontend math.
Translate English text to Pig Latin and decode back. A classic word game for all ages. Rules-based translation runs in your browser.
Start with a word and find synonyms, then synonyms of synonyms. Build a chain and explore language. Local thesaurus.
Design a humorous novelty ID card with photo, name, and random barcode. Clearly labeled 'Novelty'. Prank purpose only.
Quickly test SQL JOIN syntax (INNER, LEFT, RIGHT, FULL) with a sample database schema. Check logic and see conceptual result set without a real DB. Local only.
Check if a word or phrase is a palindrome (reads same forward and backward). Live validation and fun facts.
Build 'I feel... when... because...' statements interactively. Improve communication in relationships. Local only.
Use the new `commandfor` and `command` attributes to invoke actions on other elements without JavaScript. See the spec live.