Fast, browser-based developer tools.
Everything runs locally — nothing leaves your device.
58
Tools
6
Categories
100%
Local
A complete toolbox for developers — that respects your privacy
elefcode is a free collection of 58 developer utilities that run entirely in your browser. It brings the small tools you reach for every day — formatters, converters, encoders, generators, and calculators — into one fast, consistent workspace. There is nothing to install and no account to create: open a page and start working.
The defining feature is privacy. elefcode has no backend and no database. Whatever you paste, type, or upload is processed by JavaScript on your own device using standard browser APIs — the Web Crypto API for hashing and encryption, Canvas for image work, and more. Because your data never reaches a server, sensitive input like tokens, keys, config files, and photos stays with you.
The tools are organized into clear categories: Format & Validate for JSON and structured data, Security & Encoding for JWTs, hashing, and AES, Dev Utilities for everyday conversions, Text & Data for transforming content, and Design & Visual for colors, CSS, and images. New tools are added regularly.
Want to understand the concepts behind the tools? Our Guides explain topics like how JWTs work, what Base64 really does, cron syntax, Unix permissions, and more — in plain English, each linked to a tool you can try right away.
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Format & Validate
Parse, diff, and preview structured data and text.
JSON Formatter
Pretty-print and validate JSON payloads. Monaco-powered editor with shareable URLs.
JSON → TypeScript
Generate TypeScript interfaces from any JSON. Handles nested objects, arrays, and optional fields.
Diff Viewer
Compare two texts side by side with line, word, or character diff highlighting.
Markdown Preview
Live GFM editor with real-time HTML preview. Tables, code blocks, task lists, shareable URL.
Regex Tester
Live match highlighting across test strings with flag toggles and capture group table.
SQL Formatter
Pretty-print SQL across MySQL, PostgreSQL, SQL Server, and more, with keyword casing and indent options.
Code Beautifier
Beautify or minify HTML, CSS, and JavaScript — format messy code or shrink it for production.
Security & Encoding
Decode tokens, hash data, and encode content securely.
JWT Decoder
Decode header, payload, and check expiry without needing the secret key.
Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512 from text or file via the browser's Web Crypto API.
Password Generator
Cryptographically secure passwords with custom length, charset options, and entropy meter.
Base64 Encoder
Encode or decode Base64 strings and files. URL-safe mode and drag-and-drop support.
HMAC Generator
Generate and verify HMAC-SHA256/384/512 signatures via Web Crypto. Hex, Base64, Base64url output.
JWT Builder
Sign JSON Web Tokens with HS256/384/512. Custom payload, expiry, and secret — in-browser.
QR Code Generator
Generate QR codes for any URL or text. Custom size, colors, error correction. Download PNG/SVG.
AES Encrypt / Decrypt
Password-based AES-256-GCM encryption via Web Crypto. Salt + IV packed into the output. Fully local.
Bcrypt Generator
Hash passwords with an adjustable cost factor and verify a password against an existing hash.
Basic Auth Header
Turn a username and password into an Authorization: Basic header, Base64 creds, and curl example.
Dev Utilities
Everyday developer conversions and calculators.
chmod Calculator
Click read/write/execute boxes to get octal (755) and symbolic (rwxr-xr-x) permissions and the command.
Slugify
Turn any text into a clean URL-safe slug with accent stripping and separator options.
String Escape
Escape text for JSON, JavaScript, SQL, shell, regex, HTML, or URLs with one click.
.env ↔ JSON
Parse dotenv files into JSON or turn a JSON object back into a .env file, with quoting handled.
YAML ↔ JSON
Convert YAML config to JSON and back instantly, with error reporting. Runs in your browser.
UTM Builder
Add utm_source, utm_medium, and campaign tags to any link for Google Analytics tracking.
.gitignore Generator
Pick your languages, frameworks, editors, and OSes to build a ready-to-use .gitignore file.
HTTP Status Codes
A searchable reference of every common HTTP status code — 200, 301, 401, 404, 500 — and what it means.
Generators
Generate IDs, schedules, and time values on demand.
UUID Generator
Generate UUID v4 and v7 in bulk using Web Crypto. Copy individually or all at once.
Cron Generator
Parse any cron expression and preview the next 5 scheduled execution times instantly.
Timestamp
Convert Unix epochs to human dates and back. Live clock. Auto-detects seconds vs ms.
Fake Data Generator
Generate dummy names, emails, and addresses as JSON, CSV, or SQL to seed databases and tests.
Text & Data
Transform, count, generate, and encode text and numbers.
Case Converter
Convert between camelCase, snake_case, kebab-case, PascalCase, CONSTANT, Title Case and more.
Word Counter
Live word, character, sentence, and paragraph counts with reading time and word frequency.
Lorem Ipsum
Generate placeholder text by paragraphs, sentences, words, or bullet lists. One-click copy.
URL Encoder
Percent-encode and decode URLs and query strings with a live query-parameter breakdown.
HTML Entities
Escape and unescape HTML entities like < & ", or encode all non-ASCII characters.
Number Base
Convert between binary, octal, decimal, and hexadecimal live. Handles very large integers.
Text Diff
Compare two blocks of text and highlight additions and deletions word by word or line by line.
Text Sorter & Dedup
Sort lines alphabetically, numerically, or by length, remove duplicates, reverse, or shuffle.
JSON ↔ CSV
Convert a JSON array of objects to CSV and back, with custom delimiters and type coercion.
CSV Viewer / Editor
Paste or upload CSV to a sortable, editable table — add rows, rename columns, then export.
Markdown Table
Fill a visual grid, set column alignment, and copy a clean GitHub-flavored markdown table.
ASCII / Unicode
Look up any character's code point, HTML entity, CSS/JS escape, and UTF-8 bytes. ASCII table included.
Text to Speech
Read text aloud with your browser's built-in voices and adjustable rate, pitch, and volume.
Fancy Text
Turn text into bold, cursive, gothic, and bubble Unicode fonts to copy into social bios and posts.
Design & Visual
Build visuals, optimize assets, and generate markup.
Color Converter
Convert HEX · RGB · HSL · HSV with live sliders. WCAG contrast ratio checker included.
CSS Gradient
Build linear, radial, and conic gradients visually. 7 presets, adjustable stops.
Meta Tag Generator
Generate SEO + Open Graph + Twitter Card tags with live Google and social preview.
SVG Optimizer
Remove Inkscape/Illustrator metadata, comments, and editor bloat from SVG files.
Mermaid Diagram
16 diagram types — flowcharts, ER, Gantt, Git graphs, mindmaps, and more.
Box Shadow Generator
Stack multiple box-shadow layers with live sliders for offset, blur, spread, and opacity. Copy CSS.
Border Radius Generator
Round each corner independently in px or %, preview the shape, and copy the shorthand.
Flexbox / Grid Playground
Toggle justify, align, direction, columns, and gaps. Live layout preview and copyable CSS.
Contrast Checker
WCAG contrast ratio with AA / AAA pass-fail for normal text, large text, and UI components.
Favicon Generator
Render every favicon size from one image, with padding and circle-mask, plus HTML and manifest.
Image Compressor
Re-encode and resize images to WebP, JPEG, or PNG with a live size-saved readout. Fully local.
Image → Base64
Convert an image to a data URI with ready-made CSS background and img-tag snippets.
cubic-bezier Editor
Drag control points to design a CSS easing curve, preview the animation, and copy the value.
EXIF Viewer & Remover
Inspect a photo's hidden metadata and GPS location, then download a clean copy with it stripped.
Image Color Picker
Upload a photo and pick any pixel to get its HEX, RGB, and HSL, with a magnifier and palette.