🌀 Rotating Rings — Stare at the centre and the concentric ring pattern appears to physically rotate. High-contrast luminance steps misfiring motion-detector cells in your peripheral vision — a Peripheral Drift effect. 🧱 Café Wall — Perfectly parallel horizontal lines appear to converge like trapezoids. The grey mortar joints between offset black-and-white tiles confuse orientation-selective neurons. Row offset and mortar thickness are both adjustable. ⬛ Hermann Grid — Grey ghost dots appear at the intersections between white squares, then vanish when you look directly at them. Caused by lateral inhibition in the retinal ganglion cells. 💃 Spinning Dancer — The silhouette dancer can be seen spinning either clockwise or counterclockwise. Focus on the foot or the shadow to flip the perceived direction of rotation. ⭕ Ebbinghaus Illusion — Two identical circles look different in size depending on the size of the surrounding circles. A slider controls the surround size so you can strengthen or weaken the effect. ↔️ Müller-Lyer — Identical line segments look different in length depending on the direction of the arrowheads. Arrowhead size and line length are both adjustable. An "EQUAL" bracket on the right confirms the lines are the same. 🏺 Rubin's Vase — The image can be read as either a white vase or two faces looking at each other. A classic figure–ground illusion where both interpretations compete inside the brain. 💧 Motion Aftereffect — Stare at the flowing stripes on the left for 20 seconds, then shift your gaze to the static grid on the right — the grid will appear to drift in the opposite direction. A static demonstration of the Waterfall Illusion. 🔲 Simultaneous Contrast — Two squares of identical grey (RGB 128) look dramatically different in brightness depending on the background behind them. A BG contrast slider lets you tune the strength of the effect. ⚡ Scintillating Grid — White dots at intersections seem to flicker and disappear as your eyes move across the pattern. An enhanced version of the Hermann Grid, with adjustable square size, gap, and dot radius. 📦 Necker Cube — A wire-frame cube appears to project outward in two different directions, and your perception flips as you stare at it. The brain alternates between two equally valid 3D interpretations in the absence of depth cues. 👁 Troxler's Fading — Fix your gaze on the central cross without moving your eyes and the surrounding coloured ring slowly fades and disappears. Neural adaptation reduces the brain's response to unchanging stimuli — revealing how much of your visual field is actively ignored.

10 interactive Network Effects visualizers! 📡 Metcalfe's Law — Animates every edge formed as n users connect in real time. Adjust the user count slider and the number of connections (n(n-1)/2) and network value (n²) update instantly. A comparison chart overlays the Linear, Metcalfe, and Reed's Law growth curves side by side. 📈 Adoption Curve — Rogers' technology adoption S-curve unfolds along a time axis. Adjust the tipping point position and growth rate k to visualise the exact moment of "crossing the chasm," with a five-segment adoption band (Innovators → Laggards) displayed below the chart. 🦠 Viral Spreading (SIR) — 200 particles move between S (blue), I (red), and R (grey) states as the epidemic spreads. An R₀ = β/γ gauge updates in real time — above 1 the infection spreads, below 1 it dies out. Includes an explanation of how this maps to the product K-factor. 🗂️ Network Types — Five types (Direct, Indirect, Data, Social, Local) are laid out as interactive cards, each containing a live mini network graph of its own structure. A bar chart at the bottom compares the competitive moat strength of each type. 💥 Critical Mass — A live level gauge and time-series chart show whether a network self-sustains or collapses depending on whether it sits above or below the threshold. Adjust the threshold and seed percentage to catch the exact moment a tipping point is crossed. 🏗️ Platform Competition — A pie chart and time-series graph together show how two platforms' market shares converge toward natural monopoly under network effects. Tune initial size and product quality to experiment with the conditions that trigger Winner-Take-All dominance. 🌀 Churn & Retention — A spinning flywheel diagram visualises how retention rate, viral coefficient, and new user acquisition interlock. The long-run user count trend and LTV estimate update in real time as you adjust the sliders. 🌍 Geographic Spread — Diffusion waves (expanding rings) radiate from the launch city and claim neighbouring cities one by one. A cascade effect is implemented — an adopted city shortens the adoption timer of nearby cities — letting you experience the city-by-city rollout strategy used by Uber and Airbnb. 📱 Social Network — Nodes are added in real time through invite loops, and nodes with more connections are rendered larger. The right-hand panel covers social graph growth insights including Facebook's north-star metric of "7 friends in 10 days." 🛒 Marketplace (Two-Sided) — Live transactions (yellow $ particles) flow back and forth between the buyer zone (blue) and seller zone (green), and both sides grow automatically as transactions accumulate. The right panel explains liquidity score, the cold-start problem, and the concept of rake rate.

Sorting — 6 Algorithms 🫧 Bubble Sort — Compares adjacent elements and "bubbles" the larger value to the right. Each pass is colour-coded to show the maximum value settling at the end. Live counters track comparisons (red), swaps (yellow), and sorted elements (green). 🎯 Selection Sort — Scans the unsorted region for the minimum value (blue pivot · orange current minimum) and swaps it to the front. Always performs O(n²) comparisons, but keeps the number of swaps to a minimum. 📌 Insertion Sort — Takes the next element and inserts it into its correct position within the already-sorted region. An adaptive algorithm that approaches O(n) on nearly-sorted arrays. 🔀 Merge Sort — Recursively splits the array in half, then merges the halves back together. The merge step — comparing two sub-arrays and placing elements in order — is shown as blue bars. Stable sort with a guaranteed O(n log n) time. ⚡ Quick Sort — Picks a pivot (orange) and partitions the array so smaller values go left and larger values go right, then recurses on each side. Average O(n log n), worst case O(n²). Once a pivot's final position is confirmed, it turns green. 🏔️ Heap Sort — Builds a Max-Heap from the array (heapification), then repeatedly extracts the root (maximum). In-place sort with a guaranteed O(n log n) time. Graph — 4 Algorithms 🌊 BFS — Explores outward from the start node one layer (hop) at a time. Guarantees the shortest path by hop count in unweighted graphs, then traces the route back through parent pointers once the goal is reached. 🔍 DFS — Recurses as deep as possible along each branch before backtracking. Does not guarantee the shortest path, but is the foundation for connectivity checks, topological sorting, and cycle detection. 🗺️ Dijkstra — Finds the true shortest distance in a weighted graph. A priority queue ensures the lowest-cost node is always processed first; edge weights are displayed inside each node. ⭐ A* — Dijkstra plus a heuristic (Euclidean distance to the goal). The formula f(n) = g(n) + h(n) steers the search toward the target, making it faster than Dijkstra in practice. Guarantees an optimal path as long as the heuristic is admissible.

An eleven-experiment high school chemistry lab visualiser! 🦷 Elephant Toothpaste — Raise the H₂O₂ concentration and KI catalyst sliders to watch foam erupt in real time. Includes a live reaction rate meter (%), a temperature gauge showing the exothermic heat release, and a full equation panel. 🌋 Baking Soda Volcano — Press the ERUPT! button on the 3D volcano to trigger a burst of CO₂ bubbles and flowing lava. Demonstrates the NaHCO₃ + CH₃COOH acid-base neutralisation reaction. 🟢 Polymer Slime — Click and drag to pull the slime blob around. PVA and borax sliders adjust cross-link density in real time, changing viscosity, elasticity, and stretchiness on the fly. 💡 Lava Lamp — Simulates density changes with a temperature slider. Heated wax becomes less dense and rises; it cools at the top, regains density, and sinks. Includes a "Like Dissolves Like" polarity guide and a density comparison chart. 🌈 pH Color Indicator — Sliding the pH scale from 1 to 14 shifts the red cabbage juice indicator through red → orange → yellow → green → blue → purple. Features seven reference test tubes and a table of everyday substances with their pH values. 🖊️ Chromatography — Solvent climbs the paper strip and separates six pigments according to their Rf values, with each band's Rf displayed live. Also covers five types of chromatography from paper to HPLC. 💎 Crystal Growing — Adjust concentration and temperature until the solution enters the supersaturated zone — crystals nucleate and grow in real time. The solubility curve marks your current state, accompanied by hexagonal crystal system graphics. ⚡ Electrolysis — Voltage and electrolyte concentration sliders control the rate of H₂ (blue bubbles) and O₂ (red bubbles) production at a 2:1 ratio. Animated electrode half-reactions and ion migration are shown inside the cell. 🔋 Fruit Battery — Click lemon, orange, apple, or potato tabs and stack cells in series to add voltages — the LED lights up once total voltage exceeds 1.5 V. Demonstrates the galvanic cell principle with half-reaction equations. 🧊 Endothermic Mix — Increasing the Ba(OH)₂ + NH₄SCN reagent amount drives the temperature down to −20°C, triggering a snowflake and frost animation. An energy profile diagram shows ΔH > 0. 🔥 Exothermic Reaction — Raising the Mg + H₂SO₄ concentration and temperature accelerates the reaction, spawning flame and spark particles. Includes an Arrhenius rate law visualisation and an energy profile diagram with activation energy marked.

A ten-concept drone explorer, dark-themed throughout! ✈️ Flight Mechanics — Four forces (Lift, Weight, Thrust, Drag) drawn as live vectors. Throttle slider controls altitude state (Ascending / Hovering / Descending), and the wind slider adds crosswind compensation arrows showing how the FC counters drift. Motor RPM gauge updates in real time. 🎮 Maneuvers — Roll, Pitch, and Yaw demonstrated side by side with clickable tiles. The main drone animates the selected axis, while the Motor Mix panel shows which motors spin faster or slower to achieve each maneuver. RC stick mapping diagram included. ⚡ Motors & Propellers — Top-down quadrotor view showing CW/CCW spin directions with animated blur. A Thrust vs RPM² curve plots current operating point. Propeller efficiency metrics (mN/W), counter-rotation torque cancellation explanation, and a full thrust/power breakdown panel. 🏖️ Beach Filming — Golden-hour coastal scene with animated waves, foam, parasols, and people on a sandy beach. Drone flies overhead with a camera FOV cone showing coverage width. Altitude slider changes the shot type automatically (Reveal → Orbit → Top-Down). Cinematic shot guide and camera tech specs (5.1K / 3-axis gimbal / ND filters). 📦 Delivery Drone — Full 4-phase delivery cycle animated over a city skyline: Takeoff → En Route → Descent → Delivery, with payload box hanging below and a ground drop confirmation. Phase timeline at the bottom, industry leader badges (Amazon, Wing, Zipline). 🗺️ Surveying & Mapping — Drone lawnmower grid-scan with blue overlay showing photographed area, overlap zones in green, and a photo counter. GSD, altitude, accuracy, and the full 7-step photogrammetry pipeline (SfM → point cloud → mesh → orthomosaic) displayed with status indicators. 🚨 Search & Rescue — Night forest scene with thermal heat signatures showing survivors as orange blobs. Drone spirals outward on an expanding search pattern; when it passes within detection range, a survivor is marked FOUND ✓ in green. FLIR specs and why thermal works through vegetation explained. 🌾 Agriculture — Three clickable modes: Crop Spraying (blue particle stream), NDVI Scan (coloured health map per field block), and Precision Seeding. Lawnmower flight path over a farm field, with stats comparing drone vs traditional tractor: 30–50% less chemical, 10× faster, one operator. 🏁 FPV Racing — Full FPV HUD with crosshair, speed readout, gate counter, and battery voltage. Drone autonomously threads five numbered gates around a track with motion blur and glow effects. Scanline overlay gives an authentic goggle feel. 5-inch race drone spec sheet included. 🎯 Military & Recon — Three modes (ISR Surveillance, Strike Simulation, Electronic Warfare) on a radar-sweep map view. MQ-9 Reaper flying wing silhouette with sensor ball. ISR shows coverage radius with target markers; strike shows trajectory arc; EW shows expanding jamming waveform. Full Reaper spec sheet (27hr endurance, 15,000m ceiling, 20m wingspan).

Freedom to Create. Your idea. Your creation. Your freedom.

MULTI-VECTOR CHECK 🌐 GEO LOCATION | ipapi.co | Country, City, ISP, Timezone, Coordinates 🔤 REVERSE DNS | Cloudflare DoH PTR | Reverse DNS Hostname 📡 HTTP LATENCY | 6 fetch measurements | Min/Max/Median + Mini Bar Chart 🗂️ DNS RECORDS | Cloudflare DoH | A, AAAA, MX, NS, TXT, CNAME 📋 WHOIS / ASN | rdap.org | Network Name, Handle, CIDR / Domain Registration Info 🔌 PORT PROBE | fetch timeout detection | 80, 443, 8080, 8443, 21, 22 OPEN/CLOSED/FILTERED 🔒 DNS-over-HTTPS | Cloudflare, Google, Quad9 | DoH Response Time Comparison 🛡️ THREAT INTEL | Type Analysis | Hosting / Private / Residential ISP Classification

자동 표시 (페이지 로드 시) ✅ Public IP — IPv4/IPv6 구분, ASN·ISP 표시 ✅ 위치 — 국가 🏳️ + 도시, 지역, 시간대, 좌표 ✅ 레이턴시 — 초기 Cloudflare 핑 측정 속도 테스트 버튼 클릭 시 ✅ PING → 5회 측정 후 중앙값 / 최솟값 / 최댓값 ✅ 다운로드 → Cloudflare speed.cloudflare.com 에서 1MB → 5MB → 10MB → 25MB 순차 청크 다운로드, 스트림 중 실시간 샘플링 ✅ 업로드 → 2MB 랜덤 바이너리 4회 POST ✅ 실시간 오실로스코프 그래프 — Canvas로 직접 렌더링, Y축 자동 스케일, ✅ 글로우 라인 + 페이드 필, 리딩 닷 애니메이션 ✅ 상세 결과 테이블 — 평균/최대/측정 시각

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JSON utilities are tools and classes used to read, write, format (beautify), and validate JSON data, or to convert between objects and text in programming languages.

A nine-concept gear mechanics explorer! ⚙️ Spur Gears — The most fundamental gear type. A real-time animation shows two gears meshing and spinning in opposite directions. The contact point (red dot), pitch circles (dashed lines), and rotation arrows update instantly as you adjust the gear ratio and speed sliders. 🌀 Helical Gears — Angled teeth engage gradually for smoother, quieter operation. Drag the helix angle slider to change the spiral angle and watch the axial thrust arrows respond. A Spur vs Helical comparison table covers noise, load capacity, efficiency, and axial thrust side by side. 🔺 Bevel Gears — Redirect power through a 90° corner. Two gears mesh at a right angle in a perspective-style view. A diagram explains how the automotive differential works and why the inner and outer wheels rotate at different speeds when cornering. 🐛 Worm Gears — A worm screw drives a worm wheel. The Starts slider switches between 1 and 4 thread starts, instantly updating gear ratio, efficiency, and self-locking status. A single start = self-locking — the principle behind elevator hoists. 🪐 Planetary Gears — Gear ratio changes depending on which element (sun, ring, or carrier) is held fixed. Click the three mode buttons at the bottom to experience the logic behind automatic transmission gear selection. 📐 Rack & Pinion — Pinion rotation → rack linear travel. Alongside a car steering mechanism sketch, the linear velocity formula v = ω × R is explained with real-world examples: CNC machine axes, camera sliders, and cog railways. 📊 Gear Ratio — Raise the ratio slider: speed ↓, torque ↑. Lower it: speed ↑, torque ↓. Both are shown live through vectors and a speed-vs-torque crossover chart that visualises conservation of energy. 🔗 Compound Train — Three reduction stages spin simultaneously (4:1 × 4:1 × 4:1 = 64:1). Colour-coded shafts make it immediately clear how each stage's ratio multiplies into the total, achieving extreme reduction in a compact space.

An eight-concept game theory explorer! 🔒 Prisoner's Dilemma — The classic paradox made interactive. Click Cooperate or Betray for each prisoner and immediately see the prison sentence outcome. A live round history tracks patterns. The Nash Equilibrium cell (Betray/Betray) is permanently highlighted — rational choice leads to collectively worse outcomes. ⚖️ Nash Equilibrium — Three games with different equilibrium structures: Rock-Paper-Scissors (no pure Nash, only mixed), Battle of the Sexes (two equilibria), and Stag Hunt (two equilibria with different risk profiles). Switch between games with tabs; Nash cells pulse with a golden glow. 👑 Dominant Strategy — The advertising duopoly shows why firms always advertise even when both would profit more if neither did. Step-by-step Iterated Elimination of Dominated Strategies (IEDS) is laid out as a four-step flowchart. ⚔️ Zero-Sum Games — A 4×4 military payoff matrix with click-to-inspect cells. A saddle point is automatically found and highlighted. A live pie chart shows the zero-sum constraint visually — one player's gain is always the other's loss. The Minimax Theorem is shown numerically. 🧬 Evolutionary Game Theory — A live population simulation of Hawks vs Doves competing over generations. Watch the population chart evolve in real time as natural selection finds the Evolutionarily Stable Strategy (ESS). Mutation slider introduces randomness; a fitness comparison shows which strategy is currently winning. 🏷️ Auction Theory — Compare all four standard auction formats side by side: English, Dutch, First-Price Sealed, and Vickrey (Second-Price). Bid bars show true values vs actual bids, winner's surplus, and price paid. The Winner's Curse and Revenue Equivalence Theorem are explained with context. 🤝 Bargaining Game — An animated pie that responds to split and patience sliders in real time. The Rubinstein alternating-offers formula calculates the mathematically predicted split based on patience. The Ultimatum

A nine-concept fluid mechanics explorer! 💧 Fluid Properties — Click any of the five fluids (air, water, engine oil, honey, blood) to see viscosity and density change in real time, with the particle motion inside the container responding accordingly. Pressure arrows show how hydrostatic pressure increases with depth. 📊 Pascal's Law — Press the PUSH button to transmit a small piston force to a much larger piston, lifting the car. The formula F₂ = F₁ × (A₂/A₁) is computed live. This is the principle behind car brakes, hydraulic lifts, and excavators. 🌀 Bernoulli's Principle — As the pipe narrows in the middle, airspeed rises and pressure drops — visualised through pressure gauges and particle colour. P + ½ρv² = constant. 🔄 Continuity Equation — A₁v₁ = A₂v₂. Drag the pipe cross-section slider and watch flow velocity automatically increase at the narrow section. Particle colour shifts from blue (slow) to red (fast). 〰️ Laminar vs Turbulent — Slide the Reynolds Number to switch between laminar flow (Re < 2300, smooth parallel blue streams), the transitional zone, and turbulent flow (Re > 4000, chaotic red mixing). In laminar mode, the parabolic velocity profile is drawn across the pipe. 🚗 Drag & Lift — Streamlines above and below the airfoil are drawn in real time (blue = high pressure, red = low pressure), and the lift and drag force vectors update as you adjust angle of attack and speed. Includes a drag coefficient comparison by shape (flat plate 1.17 → airfoil 0.012). 🔩 Pipe Flow — Calculates frictional head loss using the Darcy-Weisbach equation (h_L = f·L/D·v²/2g). Diameter, length, and velocity sliders instantly update Reynolds number, friction factor f, and total head loss. ⚙️ Pumps & Turbines — Four machine types: centrifugal pump (spinning impeller), axial turbine (hydropower), Pelton wheel (impulse turbine), and a pump-system curve graph (showing the operating point). RPM slider adjusts rotational speed. 🌍 Real World — Four detailed case studies with equations and animations: aircraft wing (2.7 MN of lift), ship hull (Archimedes buoyancy), blood circulation (non-Newtonian, pulsatile flow), and wind turbines (Betz limit: 59.3% maximum extractable power).

개발자용 네이밍 케이스 8종 camelCase · PascalCase · snake_case · SCREAMING_SNAKE · kebab-case · UPPER-KEBAB · dot.case · path/case 특수 변환 13종 전각/반각 · 스몰 캡스 · 위/아래 첨자 · 취소선 · 밑줄 · 버블 텍스트 · 사각 텍스트 · 모스 부호 · 이진수(ASCII) · ROT13 추가 도구 • 텍스트 정리: 공백 제거, 빈 줄 제거, 중복 줄 제거, 줄 정렬, 줄 번호 추가/제거, 텍스트 뒤집기, 섞기 • 찾아 바꾸기: 정규식 지원, 대소문자 구분, 자주 쓰는 패턴 퀵버튼

Pre-algebra is a common name for a course taught in middle school mathematics in the United States, usually taught in the 6th, 7th, 8th, or 9th grade.

AI 정규표현식 Generator & Tester

|카테고리 |단위 수|특이 단위 | |-----|----|----------------------| |📏 길이 |13개 |광년, 천문단위, 해리 포함 | |⚖️ 무게 |8개 |한국 근 포함 | |🌡️ 온도 |4개 |섭씨·화씨·켈빈·랭킨 (별도 공식 적용)| |🗺️ 넓이 |12개 |평(한국) 포함 | |🧪 부피 |13개 |갤런, 쿼트, 컵 | |🚀 속도 |7개 |마하, 광속 포함 | |⏱️ 시간 |10개 |나노초까지 | |💾 데이터|11개 |SI(KB)와 이진(KiB) 구분 | |🔵 압력 |9개 |atm, bar, psi, mmHg | |⚡ 에너지|9개 |kcal, kWh, eV, BTU | |📐 각도 |6개 |라디안, 그라디안, 분·초 | |🍳 요리 |10개 |한국 컵(200mL)/큰술/작은술 별도 |

✍️ 입력 상단 고정 입력창 — 스크롤해도 항상 위에 있음 #태그 입력 시 실시간 자동완성 드롭다운 (기존 태그 목록 + 사용 횟수) ★ 중요 표시 6가지 컬러 라벨 (왼쪽 테두리 색상으로 구분) ⌘Enter / Ctrl+Enter 단축키 저장 🗂 관리 카드 hover 시 편집 / 고정 / 삭제 버튼 노출 인라인 편집 (카드 안에서 바로 수정) 📌 고정 메모 항상 상단 배치 긴 메모 자동 접기 + "더 보기" 모달 🔍 탐색 상단바 실시간 검색 전체 / 고정 / 중요 탭 필터 태그별 필터 (태그 클릭으로 토글) 최신순 / 오래된순 / 가나다순 정렬 📊 통계 전체 / 고정 / 태그 종류 / 중요 표시 수 실시간 집계 🎨 UX 다크모드 토글 (상태 기억) 새 카드 슬라이드 인 애니메이션 모바일 FAB 버튼 (✏️) txt 파일 내보내기 localStorage 영구 저장

✅ 피커: RGB 슬라이더 + HEX 직접 입력 + HSL 변환 표시 ✅ 팔레트 생성: 보색·유사색·3색·4색·모노크롬·랜덤 자동 생성 ✅ 팔레트 뷰어: 큰 스트립 + 개별 카드 (클릭 복사) ✅ 색상 정보: HEX / RGB / HSL / HSB / CMYK 동시 표시 ✅ 저장: localStorage 팔레트 북마크 ✅ 내보내기: CSS 변수 / Tailwind config / JSON

✅ RDAP API (Verisign 공식) — 완전 무료, 인증 불필요, CORS 허용 ✅ 등록일 / 최종수정일 / 만료일 / 등록기관 / 네임서버 표시 ✅ 만료 90일 이내면 노란색 ⚠ 경고 표시 ✅ 미등록 도메인은 별도 메시지로 구분 ✅ 최근 조회 이력 칩 (localStorage) ✅ 총 70개 TLD 지원, 각 TLD마다 공식 RDAP 엔드포인트 매핑 Generic: .com .net .org .info .biz 등 New gTLD: .app .dev .io .ai .shop .tech .blog 등 ccTLD: .kr .jp .de .uk .cn .fr .au 등