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Black Hole Imager
See a spinning black hole as it would really look: every pixel is a light ray traced through the Kerr spacetime, with frame dragging, Doppler and gravitational shifts, an accretion disk and your own 3D objects.
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Black Hole Imager
See a spinning black hole as it would really look: every pixel is a light ray traced through the Kerr spacetime, with frame dragging, Doppler and gravitational shifts, an accretion disk and your own 3D objects.
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Image Converter & Compressor
Resize, convert (PNG, JPEG, WebP) and compress images right in your browser – nothing is uploaded.
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Black Hole Simulator
Launch particles, light rays and spaceships around a spinning black hole – orbits, light bending, frame dragging and time dilation.
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Audio Converter
Convert MP3, WAV, FLAC, OGG, AAC, M4A and more to WAV, MP3 or WebM/Opus – batch processing, right in your browser.
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.htaccess & Nginx Config Generator
Build HTTPS and www redirects, caching, compression, security headers and error pages – output for Apache .htaccess and Nginx side by side.
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.htpasswd Generator
Generate and verify .htpasswd entries for HTTP Basic Auth – bcrypt, APR1-MD5 or SHA-1 – plus the matching Apache and Nginx config.
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AES Text Encryption
Encrypt and decrypt text with a passphrase – AES-256-GCM, or OpenSSL-compatible AES-256-CBC that you can decrypt with openssl enc.
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API Request Tool
Build, send and inspect HTTP requests in your browser – all methods, headers, bodies and auth, with a searchable JSON viewer.
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Base64 Encoder / Decoder
Encode and decode Base64 / Base64URL with full UTF-8 support, turn files into data URIs and decode Base64 back into downloadable files.
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bcrypt Hash Generator
Create and verify bcrypt hashes compatible with PHP password_hash() / password_verify(), Laravel and most frameworks. Adjustable cost.
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BPM Tapper & Metronome
Tap along to find the tempo of any track, then keep time with an accurate Web Audio metronome with accents and a delay-time chart.
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Browser & Device Info
Everything your browser reveals: user agent, screen and viewport, pixel ratio, languages, time zone, supported features and media queries.
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Case Converter & Slugify
Convert text between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case and more, and create clean URL slugs.
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chmod Calculator
Toggle read / write / execute and get octal (755) and symbolic (rwxr-xr-x) notation, including setuid, setgid and sticky bits.
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Classic Cipher Workbench
Caesar, ROT13, ROT47, Atbash, Vigenère, XOR, Bacon and Morse code (with audio) – plus a Caesar brute-force view for puzzles and CTFs.
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Color Converter & Contrast
Convert between HEX, RGB, HSL, HWB, CMYK and OKLCH and check WCAG contrast ratios for text and UI.
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Cron Expression Explainer
Translate cron expressions into plain English and list the next run times. Presets and a field-by-field reference included.
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CSS & HTML Minifier
Minify or prettify CSS and HTML and see exactly how many bytes you saved.
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CSS Box Shadow Generator
Layer multiple box-shadows with a live preview, inset support and copy-ready CSS.
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CSS Gradient Generator
Design linear, radial and conic gradients visually with multiple color stops and copy the CSS.
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CSV Converter
Convert CSV to JSON, SQL INSERT statements, Markdown or HTML tables – and JSON back to CSV. Detects the delimiter automatically.
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Encoding Workbench
Type once, see every encoding: hex, binary, octal, byte values, Base32, Base58, Ascii85, quoted-printable, punycode and escapes – and decode them back.
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Favicon Generator
Turn an image, emoji or letters into favicon.ico plus every PNG size and the matching HTML tags.
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Finance Dashboard
Track recurring income and expenses, one-time and irregular payments, loans and debts – with live charts and JSON backup.
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Floor Plan Designer
Draw 2D floor plans for horror survival games: rooms, doors and windows, furniture, spawns, keys, traps and designer notes.
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Hash & Checksum Generator
MD5, SHA-1, SHA-256/384/512 and CRC32 for text or files, HMAC signing, checksum comparison and hash type identification.
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HTTP Status Codes
Searchable reference of all HTTP status codes with their meaning, typical use and gotchas.
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Image Converter
Convert images between PNG, JPEG, WebP, AVIF, BMP, ICO and GIF with quality, resize and background options – no uploads.
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JSON Formatter & Validator
Pretty-print, minify, sort keys and validate JSON with exact error positions. Includes a collapsible tree view that shows the path of any value.
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JSON to Code Converter
Turn JSON into PHP arrays, TypeScript interfaces, YAML, XML, Go structs or a URL query string.
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JWT Debugger
Decode JSON Web Tokens, read claims with human-readable dates, verify HS / RS / ES signatures and sign new HS256 tokens.
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Line Tools
Sort, deduplicate, trim, reverse, shuffle, number, filter, split or join lines of text – chain as many steps as you like.
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Lorem Ipsum & Test Data
Placeholder text as paragraphs, sentences or HTML – plus fake test records (names, e-mails, addresses, dates) as JSON, CSV or SQL.
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Markdown Editor
A private Markdown editor with live preview and a clickable document outline. Open, write and save .md files – no login.
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Markdown Live Preview
Write Markdown and see the result instantly, then copy the generated HTML. Tables, fenced code, task lists and more.
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Meta & Open Graph Generator
Generate title, description, canonical, Open Graph and Twitter Card tags with a live search-result and social-card preview.
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N-Body Simulator
An interactive 2D gravity simulator: planets, binary stars, asteroid belts and colliding galaxies with real physics.
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Number Base & Bitwise Calculator
Convert between binary, octal, decimal, hex and any base up to 36 at any size, and try AND, OR, XOR, shifts and two's complement.
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Palette Generator
Color harmonies, tints and shades from one base color – or extract a palette from an image. Export as CSS variables.
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Password Generator & Strength Check
Cryptographically secure passwords and pronounceable passphrases with entropy readout – plus a local strength analyzer with crack-time estimates.
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PHP Serialize ↔ JSON
Unserialize PHP serialize() strings (WordPress options, sessions) into readable JSON and serialize JSON back – with correct UTF-8 byte lengths.
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QR Code Generator
QR codes for URLs, text, Wi-Fi logins, contacts and e-mail. Pick error correction and colors, download as PNG or SVG.
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Regex Tester
Test JavaScript regular expressions live – highlighted matches, capture groups, replace preview and a quick syntax cheat sheet.
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RSA / EC / Ed25519 Key Generator
Generate key pairs locally with WebCrypto and export them as PEM, JWK and OpenSSH public key lines.
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Secret Key & Salt Generator
One-click secrets for config files: WordPress salts, Laravel APP_KEY, Symfony APP_SECRET, Django SECRET_KEY and API tokens in hex, base64 or base62.
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SQL Formatter
Beautify or compact SQL queries – keyword casing, clause line breaks and indentation for SELECT, INSERT, UPDATE, JOINs and subqueries.
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String Escaper
Escape and unescape strings for HTML, JavaScript, JSON, PHP, SQL, regular expressions, CSV and shell arguments.
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Subnet Calculator
IPv4 and IPv6 CIDR calculator: network, broadcast, host range, masks, wildcard, binary view and subnet splitting.
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Suitefish License Manager
Issue and verify Ed25519-signed SCEL license release files – key management, signing and verification in your browser.
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Ternary Prime Laboratory
Do prime numbers hide a pattern in base 3? A live laboratory that tests the idea with exact computation, controlled statistics and the zeros behind the primes.
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Text Diff Checker
Compare two texts line by line with word-level highlights, side by side or inline, and export a unified diff.
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TOTP 2FA Generator
Create TOTP secrets with an otpauth:// QR code and compute live 6/8-digit codes to test your 2FA implementation (RFC 6238).
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Unicode Inspector
Reveal every character: code points, UTF-8 / UTF-16 bytes and HTML entities – and spot invisible or look-alike characters that break your code.
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Unix Timestamp Converter
Convert Unix timestamps (s / ms) to dates and back, see the moment in any time zone and get ISO 8601, RFC 2822 and relative formats.
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URL Encoder & Parser
Percent-encode or decode strings, split any URL into its parts and edit its query parameters in a table.
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UUID / ULID Generator
Generate UUID v4 and time-ordered v7, ULIDs and NanoIDs in bulk – and decode any UUID to see its version and timestamp.
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Word & Character Counter
Characters, words, sentences, lines, bytes, reading time, keyword density and length checks for meta titles, descriptions and posts.
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