Generators & sample files for developers and testers.
Test Data
Test Data Generator
Build a schema, export unlimited rows as JSON, CSV or SQL.
💳Credit Card Generator
Luhn-valid test card numbers + official sandbox cards.
👤Fake Person Generator
A full fake identity per country — name, address, email, phone…
🏦IBAN Generator
Generate fake but checksum-valid IBANs for 70+ countries, plus a validator.
APIFree API Directory
Search 1,600+ free public APIs by category, auth type & more.
ISOCountry & ISO Code Lookup
Look up ISO codes, calling codes, currencies & capitals for any country.
SHSelf-Hosted App Directory
Search 1,300+ free, open-source self-hostable alternatives to popular SaaS apps.
Editors & Utilities
Online Notepad
A distraction-free notepad that auto-saves in your browser.
</>Code Playground
Write HTML, CSS and JS and see the result live.
⌦Text Cleaner
Tidy up messy text with one click — trim, dedupe, sort and more.
AaCase Converter
Convert text between UPPER, lower, Title, camelCase, snake_case and more.
№Word Counter
Count words, characters, sentences, paragraphs and reading time.
¶Lorem Ipsum Generator
Generate placeholder text by paragraphs, sentences or words.
0bNumber Base Converter
Convert numbers between binary, octal, decimal, hex and any base.
⇄Palindrome Checker
Check if a word or phrase reads the same forwards and backwards.
↩Reverse Text Generator
Reverse characters, words or lines of any text.
···Morse Code Converter
Translate text to Morse code and back.
ABNATO Phonetic Alphabet
Spell out text using the NATO phonetic alphabet, or decode it back.
⇌Anagram Checker
Check if two words or phrases are anagrams of each other.
🔍AI Text Detector
Heuristic AI-likelihood text scorer
😊Sentiment Analyzer
Lexicon-based text sentiment scorer
🎙️Speech to Text
Live browser speech transcription
CSS Generators
CSS Gradient Generator
Design linear, radial and conic gradients and copy the CSS.
❏Box Shadow Generator
Build layered CSS box-shadows with a live preview.
⌒Border Radius Generator
Craft rounded corners and organic blob shapes, then copy the CSS.
⧉Flexbox Generator
Play with flex properties and copy the layout CSS.
🎨CSS Variables Generator
Build a :root CSS custom-properties block from name/value pairs.
🫧SVG Blob Generator
Generate organic, randomized blob shapes as reusable SVG paths.
🌗Color Shade & Tint Generator
Generate a full range of shades (darker) and tints (lighter) from a base color.
🎡Color Harmony Generator
Generate complementary, analogous, triadic and tetradic color schemes.
🔗Open Graph Tag Generator
Generate Open Graph meta tags with a live link-preview card.
🐦Twitter Card Generator
Generate X/Twitter Card meta tags with a live preview.
🔍SEO Meta Preview
Preview how your title and description will look in Google search results.
📏CSS Clamp() Calculator
Generate a fluid clamp() value for smoothly scaling font sizes.
Code & Converters
JSON to TypeScript
Generate TypeScript interfaces from a JSON sample.
{ }Code Formatter
Beautify or minify HTML, CSS and JavaScript.
ΔJSON Diff
Compare two JSON documents and see what changed.
✨Gitmoji Cheatsheet
Search, filter, and copy commit-ready gitmoji codes.
TOKLLM Token & Cost Calculator
Count tokens & estimate API cost for GPT-4o-style models, live.
SCHJSON Schema Generator
Infer JSON Schema, LLM function-call defs & Zod code from sample JSON.
VECEmbedding Similarity Calculator
Compute cosine similarity, Euclidean distance & dot product between vectors.
TPLAI Prompt Template Builder
Compose structured LLM prompts: role, task, examples, output format.
Crypto & Network
HMAC Generator
Compute an HMAC signature with SHA-256/384/512.
🔑Bcrypt Hash
Hash a password with bcrypt, or check one against a hash.
🔒AES Encrypt / Decrypt
Encrypt or decrypt text with a passphrase (AES-GCM).
⌗Subnet Calculator
Work out network, broadcast, mask and host range from CIDR.
UAUser-Agent Parser
Break a User-Agent string into browser, OS and device.
🔑SSH Key Generator
Generate an Ed25519 or RSA SSH key pair, entirely in your browser.
🗝️RSA Key Pair Generator
Generate a general-purpose RSA key pair as PEM, for signing or encryption.
📜X.509 Certificate Decoder
Decode a PEM certificate to see its subject, issuer, validity and more.
⏱️TOTP Code Generator
Generate live 2FA authenticator codes from a Base32 TOTP secret.
🧮Checksum Calculator
Compute CRC32/MD5/SHA-1/SHA-256/SHA-512 of text or a file, and verify against an expected value.
💪Password Strength Checker
Check a password's entropy, estimated crack time, and common weaknesses.
🎲Random Key Generator
Generate cryptographically random keys in hex, base64 or base64url.
🔄JWK Key Converter
Convert RSA/EC keys between PEM and JWK (JSON Web Key) format.
Image Tools
Image Converter
Convert images between PNG, JPG and WebP.
⤓Image Compressor
Shrink image file size with a quality slider.
⤢Image Resizer
Resize images by pixels or percentage.
◈Favicon Generator
Make favicons from an image or a letter, plus the HTML.
✂️Image Crop
Drag a selection over an image to crop it to exactly that region.
💧Image Watermark
Overlay text or a logo image onto a photo as a watermark.
🖼️Image Collage
Combine multiple photos into a single grid-layout collage image.
🔄Image Rotate & Flip
Rotate an image by 90/180/270° and flip it horizontally or vertically.
🎨Image Color Palette
Extract the dominant colors from an image as copyable hex codes.
🔍Image EXIF Viewer
View a photo's hidden EXIF metadata (camera, date, GPS) and strip it before sharing.
⭕Image Round Corners
Round the corners of an image, or crop it to a circle, with a transparent background.
🧩CSS Sprite Generator
Combine multiple icons into one sprite sheet, with matching CSS generated automatically.
🔤Image to Base64
Convert an image to a base64 data URI, or decode one back into a file.
🎛️Image Filters
Apply grayscale, sepia, brightness, contrast, blur and more to a photo.
😂Meme Generator
Add classic top and bottom caption text to an image, meme-style.
🔬Image Diff
Compare two images pixel-by-pixel and highlight exactly where they differ.
📱Social Media Image Crop
Crop and resize a photo to the exact pixel size for Instagram, Twitter/X, YouTube and more.
🖼️SVG to PNG
Rasterize an SVG vector file into a PNG or JPEG at any resolution.
⬜Image Placeholder Generator
Generate tiny blurred LQIP placeholders from a photo, or solid/gradient placeholder images.
🖨️Image Print Size Calculator
Calculate print size from pixel dimensions and DPI, or the reverse.
SVGBrand Icon Downloader
Search & download 3,400+ free SVG brand/tech logos.
BGAI Background Remover
Remove photo backgrounds with a real local AI model — no upload.
UP4XAI Image Upscaler
Upscale images 4x with a real local AI super-resolution model.
Health & Fitness
BMI Calculator
Body Mass Index calculator
🔥Calorie Calculator
BMR & TDEE calorie calculator
📏Body Fat Calculator
U.S. Navy body fat % estimator
💧Water Intake Calculator
Daily water intake estimator
❤️Heart Rate Zone Calculator
Karvonen training zone calculator
⚖️Ideal Weight Calculator
Devine, Robinson, Miller & Hamwi formulas
🤰Pregnancy Due Date Calculator
Naegele's rule due date estimator
🥑Macro Calculator
Protein, carb & fat split calculator
📄ATS Resume Scorer
Resume keyword match heuristic score
😴Sleep Cycle Calculator
Bedtime & wake-time by 90-min cycles
📐Waist-to-Hip Ratio Calculator
WHO body-fat-distribution risk indicator
🌸Ovulation Calculator
Fertile window & ovulation day estimator
🦴Body Frame Size Calculator
Small, medium or large frame from wrist ratio
🏃Walking & Running Calorie Calculator
MET-based calorie burn estimator
🚬Pack-Years Calculator
Smoking-history clinical metric
💼Freelance Rate Calculator
Hourly & daily rate from target income
📦Severance Pay Calculator
Illustrative weeks-per-year severance estimate
Project Files
.gitignore Generator
Combine language & framework templates into one .gitignore.
©License Generator
Generate a LICENSE file — MIT, Apache, GPL and more.
EC.editorconfig Generator
Generate an .editorconfig file — indent, charset, per-language overrides.
📎PDF Merge
Merge multiple PDF files into one, in your chosen order.
✂️PDF Split
Split a PDF by page ranges, or into individual pages.
🔄PDF Page Rotator
Rotate all or selected PDF pages by 90, 180 or 270 degrees.
💧PDF Watermark
Add a text watermark (e.g. "DRAFT" or "CONFIDENTIAL") to every page of a PDF.
🏷️PDF Metadata Editor
View and edit a PDF's Title, Author, Subject, Keywords and more.
🗑️PDF Page Remover
Delete specific pages from a PDF and download the result.
#️⃣PDF Page Numbers
Add page numbers to every page of a PDF, in your chosen format and position.
🖼️Images to PDF
Combine JPG or PNG images into a single PDF, one image per page.
🖼PDF Page Border
Add a decorative single or double-line border around every PDF page.
🔲PDF Crop
Crop margins from every page of a PDF by a custom amount per edge.
📑PDF Header & Footer
Add custom header and footer text to every page, with page/date placeholders.
⚖️PDF Bates Numbering
Stamp sequential Bates numbers (e.g. ABC000001) on every page, for legal document sets.
▦PDF N-up
Combine multiple PDF pages onto a single sheet (2, 4, 6 or 9 per page).
📖PDF Booklet
Reorder pages for fold-and-staple booklet printing (saddle-stitch imposition).
📋PDF Form Flattener
Convert fillable PDF form fields into permanent, non-editable page content.
➕PDF Blank Page Inserter
Insert blank pages after specific pages, or every N pages, throughout a PDF.
📄PDF Page Duplicator
Duplicate specific pages of a PDF, inserting copies right after the originals.
🗜️PDF Compress
Optimize a PDF's internal structure to reduce file size.
⬛PDF QR Stamp
Stamp a QR code encoding a URL or text onto every page of a PDF.
🔀PDF Page Reorder
Rearrange every page of a PDF into a custom new order.
🖼️PDF Extract Images
Find and download every embedded image in a PDF as separate files.
✍️PDF Form Filler
Fill in a PDF's text fields, checkboxes and dropdowns through a normal web form.
📉PDF Image Recompress
Shrink a PDF by re-compressing its embedded images at a lower quality.
🖨️PDF to Images
Render every page of a PDF as a downloadable PNG or JPEG image.
Sample & Code Files
Sample File Downloads
Download sample JSON, CSV, XML, images and sized dummy files.
</>Common Code & Config Files
phpinfo.php, .htaccess, Dockerfile, nginx.conf and more — copy or download.
❝AI Prompt Library
Searchable library of ready-to-use ChatGPT, Claude & Gemini prompts.
BKFree Programming Books
Search 2,000+ free, legal programming & CS books by subject and language.
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