Sitemap — Page 7

Read one word at a time with an eye anchor, in chunks or by sentence — and measure how many words per minute you actually read.

Find the numbers in order without moving your eyes from the center. A series of five grids gives you work efficiency, warm-up and stability.

AI builds a lesson presentation from your topic: slides, lesson plan, handout and a narrated video. PowerPoint export with speaker notes.

The periodic system, the solubility chart, the activity series of metals and a molar mass calculator on one page, with data from PubChem.

Type either box to convert. Switch modes for dates, a Roman clock, lessons, or a quiz. The chart stays visible.

Pick a level, fill in the answers, and tap Check. Earn coins, open chests, and unlock new worlds.

Adaptive algebra diagnostic for grades 5–11: shows which topics are mastered, where the gaps are, and what to study first.

Converts primary points to test scores using the official scales and helps you grade a mock exam by task and by the official FIPI criteria — the way an examiner does.

Grid, millimeter, dots, isometric, staves and handwriting guides as PDF with exact millimeters and a printer calibration.

Practice touch typing with progress tracking

Interactive alphabet guide for 12 languages. Click any letter to hear its pronunciation. Learn mode + quiz mode.

Spell numbers and amounts with real grammar — seven languages, currency, ordinals, checks and batch mode.

Free adaptive logic puzzles for kids 5–12: patterns, odd-one-out, analogies, shapes, and deduction. Voice narration and a parent skill report.

Pick an animal and a source, then drag the slider to compare your vision with theirs.

Drag any country across the map and see its real size: Mercator stops inflating it. Compare countries, states and regions by true area.

Solve equations, inequalities and systems step by step: discriminant, Vieta, domain, sign chart and a substitution check. Works from a photo.

Graph any function and get its zeros, extrema, asymptotes and intersections as numbers. Sliders for parameters, table of values, PNG and link.

Build a mind map from the keyboard, or paste a list and get a map. Share it as a link with no account; export PNG, PDF, Markdown, OPML.

Sudoku at 4×4, 6×6 and 9×9 with one verified solution and honest difficulty, plus word searches from your own list. Four to a page, PDF with answers.

Rings on its own on schedule — with a bell or a melody — and shows on screen how much time is left in the class.

Interactive multiplication chart, a times tables trainer that asks the hard facts more often, a mastery map and printable worksheets. In the browser.

Long division, multiplication, addition and subtraction step by step on grid paper: carries, remainders, repeating decimals. In your browser.

Add, subtract, multiply and divide fractions with steps: LCD, simplifying, mixed numbers, repeating decimals, GCF and LCM. In your browser.

Balance chemical equations with the oxidation-number method, find molar mass and percent composition, solve stoichiometry. In the browser.

Convert binary, octal, decimal and hex with full working: division ladder, expanded form, bit groups. Two's complement, IEEE 754. In the browser.

Truth table with a column for every step, DNF and CNF, Quine–McCluskey minimization, a Karnaugh map and a logic gate diagram. In the browser.

Triangles, quadrilaterals, circles, polygons and solids from any given data: scale drawing, every value, working with named theorems. In the browser.

Step-by-step derivatives, integrals and limits: each step names its rule and every answer is checked numerically. Runs in the browser.

Make a class schedule in two minutes: color-coded subjects, bell times, A/B weeks, 10 designs, vector PDF and a phone wallpaper. In your browser.

Encrypted diary, password manager and file safe — AES-256-GCM encryption in your browser via Web Crypto API.

Type a secret, get innocent-looking text to send anywhere; paste it back to recover the exact message.

Hide secret text, files, or images inside pictures using LSB steganography. Optional AES-256 encryption.

Generate strong random passwords

Generate strong diceware passphrases

Check password strength and crack time

Check if a password appears in known data breaches

Generate TOTP 2FA codes from an otpauth secret

Decode otpauth:// QR codes and 2FA secrets

Audit a password list for weakness and breaches

Open and view KeePass .kdbx databases

Convert Bitwarden exports between formats

Split a secret into K-of-N reconstructible shares

Share a secret via a self-destructing link

Generate PGP/GPG key pairs

What Google, Apple and password managers already offer, what to write down, and how to split the key so nobody opens the envelope alone.

Draw pictures online with brushes, shapes and colors

A board per student, no sign-up; LaTeX formulas and graphs, chalkboard and grid, PDF pages, stylus pressure. Send a link — the lesson starts.

Write a book together: start a story or add a page to someone else's. Append-only — nobody can delete your page, editable for 24h.

A free tool to draw in the air with your hand: a hand-tracking model follows your fingertip and a neon brush paints the line. Pinch your fingers to draw, open them to stop.

A picture sits semi-transparent over your camera feed so you can trace it on real paper. Outlines from photos, grid, perspective fix. In the browser.

Build a printable wall newspaper for school holidays, classroom corners or birthdays — drop in photos, text and stickers, then print across A4 sheets.

Animated ecards for any occasion: type a name and watch it shimmer in gold, with glitter and music. Save as a video, GIF or picture. In your browser.

An online tool for the flags of the world: filter by color, check the proportion and color codes, download PNG or SVG — or set the cloth waving in the wind.

Create stereoscopic 3D pictures from photos

Adjust the ring, gear and pen sliders to draw geometric spirograph curves.

Draw on the canvas — every stroke is mirrored into a symmetrical kaleidoscope pattern.

Mix colors like paint or light and get a recipe from your own paints, from a photo: proportions, white balance, batch check.

Convert between HEX, RGB, RGBA, HSL, HSLA, HWB, LAB, LCH and OKLCH. Shade and tint palette, WCAG contrast check, eyedropper.

Turn a tablet or laptop into a light box: a picture at real size in cm or inches, split into screen-sized tiles, with touch lock.

Hash any file with 6 algorithms. Verify downloads, compare files, find duplicates.

Beautify, minify, and validate JSON in the browser. Live error line/column, 2/4/Tab indent. Free, no signup.

Compare two texts side by side. Line, word and character-level diff with insertion/deletion highlighting. Free, in your browser.

Parse and explain cron expressions. See the next 10 run times in your timezone, with human-readable description and field breakdown.

Generate URL-friendly slugs from text. Transliterate Cyrillic and Latin diacritics, choose separator, strip stop words, set max length.

Parse, edit and build URL query strings. Visual table editor, automatic encode/decode, array notation, JSON export.

Convert between JSON arrays and CSV files. Auto-detect direction, configurable delimiter, type coercion, header row toggle. Free, in browser.

Beautify or minify HTML in your browser. Indent options, comment removal, void-element handling, preserves <pre>/<script>/<style> content.

Open an .md file and read it as a finished document. Edit, build tables, jump by outline, save to PDF, Word or HTML — in your browser.

Format, validate, and convert YAML in your browser. YAML ↔ JSON bidirectional, indent options, multi-document support.

Encode and decode Base64 in the browser. UTF-8 safe, URL-safe variant, file uploads. Auto-detect direction. Free.

Encode and decode URL strings in the browser. Component vs full-URL mode, + for space, auto-detect. Free.

Test JavaScript regular expressions in the browser. Highlight matches, see groups, preview replacement. Free.

Decode and inspect JSON Web Tokens in the browser. Header, payload, expiry, claims explained. No signing. Free.

Generate UUID v4 (random), v7 (time-ordered), v1 (timestamp) or Nil UUIDs in your browser. Bulk, formatted, validated. Free.

Calculate MD5, SHA-1, SHA-256, SHA-384, SHA-512 and CRC32 hashes for text or files in your browser. HMAC, hex or base64.

Identify the algorithm behind any hash: MD5, SHA-256, bcrypt, Argon2, NTLM and 50+ more. Ranked matches with hashcat & John modes. Free.

Convert TTF, OTF, WOFF and WOFF2 in any direction, subset by language, pin variable axes and repair vertical metrics. Runs in the browser.

Family safe word, the call-back rule and voice comparison with a saved sample. Disproves a "relative in trouble" call; never confirms identity.

Detect AI-generated audio content

Record audio continuously for hours.

AI security camera (people, pets, vehicles) or analyze an existing recording by timestamp. P2P, in your browser.

Browser-based baby monitor with cry detection

Download or generate sample video for player testing — 1080p / 4K H.264 MP4 catalog plus on-the-fly WebM and MP4 via MediaRecorder.

Download or generate sample audio for testing — 1 kHz tone, pink noise, custom sine/white/pink at 44.1/48/96 kHz, 16/24-bit, mono/stereo WAV.

Generate dummy files of any size from 1 KB to 10 GB. Zero, random, text or pattern bytes, custom extension, instant browser download.

Generate test images for QA — color bars, grayscale, gradient, checker, grid up to 4K. Export as PNG, JPEG or WebP with adjustable quality.

Generate test PDFs in your browser — lipsum text, multi-page sections, big table or blank. A4/Letter/Legal/A3, up to 500 pages, custom title.

Generate sample documents in browser — CSV, JSON, XML, RTF, Markdown, TXT with deterministic rows. Custom row/column count up to 100 000.

Download codec test files — H.264, H.265 HEVC, AV1, VP9, VP8 in MP4 and WebM. Verify your player and pipeline support with live browser probe.

Generate log or linear sine sweep WAV files for REW, ARTA and room measurement. 20 Hz–20 kHz, 44.1/48/96 kHz, 16/24-bit, full channel routing.

TV calibration patterns for projectors and displays — SMPTE bars, PLUGE, grayscale, focus star, HDR window, overscan. PNG up to 8K plus MP4 loops.

Generate corrupted test files for error-path QA — truncate, zero magic bytes, bit-flip, zero middle or rename extension. Browser-based.

Register a robot and get a digital passport with TRID

Convert between quaternions, Euler angles and rotation matrices

Calculate required servo torque from payload and lever

Compute steps/mm for 3D printers and CNC firmware

Calculate gear ratio, RPM and torque for gear trains

Compute robot linear speed and odometry from wheel data

ISO 13855 protective separation distance for cobots

Tune PID gains and visualize step response in real time

Design and print line-follower robot race tracks

Visualize URDF robot links, joints and meshes in browser

Explore robot arm poses with DH parameter sliders

Browser-based serial monitor for Arduino and ESP32

Look up robot vacuum error codes and fixes instantly