Recommended
JSON Formatter & Validator
Validate, format, and minify JSON with precise line/column error reporting.
Open tool
Tools
Online tools.
Small utilities that run directly in your browser. No installation is needed for converting, previewing, or generating embedded assets.
Online Tools
Editor's picks
Recommended
BLE Advertisement Parser
Break down Bluetooth LE advertisement hex payloads into AD structures and decode iBeacon or Eddystone frames.
Open tool
Recommended
ESP32 Pinout Diagram & Comparison Tool
Interactive ESP32 / ESP32-S3 / ESP32-C3 pinout diagrams with GPIO functions, strapping-pin warnings, and side-by-side board comparison.
Open tool
Data Converters
Convert values between number bases, encodings, and byte formats for firmware work.
1
Hex, Base64 & Byte Array Converter
Convert UTF-8, Hex, Base64, decimal bytes, C/C++ arrays, Uint8Array, and escaped strings in your browser.
Trending
2
JSON to C Array/Struct Converter
Convert a JSON object into a C typedef struct and a designated initializer for firmware configs.
Popular
3
Binary / Bitwise Calculator
Convert decimal, hex, binary, and octal values and run bitwise AND, OR, XOR, shift, and rotate operations.
4
Color Picker & Converter
Pick a color and convert it to HEX, RGB, HSL, HSV, RGB565, and decimal, plus generate embedded C code.
5
Image Format Converter
Convert PNG, JPG, WebP, and SVG images to PNG, JPG, or WebP with resize and background options.
JSON & Text
Format, validate, and preview JSON, Markdown, and MDX content.
6
JSON Formatter & Validator
Validate, format, and minify JSON with precise line/column error reporting.
7
MDX Preview Online
Upload an .mdx or .md file and preview the rendered Markdown/MDX content directly in your browser.
8
Regular Expression Tester
Test regex patterns against sample text with live match highlighting, capture groups, and a replace preview.
9
Markdown to HTML Converter
Convert Markdown to HTML with GitHub-flavored tables, task lists, and a live preview.
Text Case Converter
Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, and more.
URL Encoder / Decoder
Encode or decode URLs and query strings with percent-encoding, with a component/full-URI mode and form-style +.
JWT Debugger & Token Generator
Decode a JWT's header/payload, check expiry, verify HS256/384/512 signatures, and generate signed tokens in your browser.
Embedded Assets
Generate image, font, and QR code assets ready to embed in firmware.
OLED/TFT Preview & C Array Tool
Convert images to monochrome, grayscale, or RGB565 byte arrays for Arduino, ESP32, OLED, and TFT projects.
LVGL Font Converter
Create compact LVGL bitmap fonts from TTF, OTF, or WOFF files with ASCII, number, Vietnamese, or custom glyph subsets.
QR Code Generator
Create QR codes for text, URLs, Wi-Fi, email, phone, and vCards, then export PNG, SVG, or an embedded C array.
Popular
Protocol Parsers
Decode and inspect wireless protocol payloads.
Hardware References
Pinouts, board comparisons, and other quick hardware lookups.
ESP32 Pinout Diagram & Comparison Tool
Interactive ESP32 / ESP32-S3 / ESP32-C3 pinout diagrams with GPIO functions, strapping-pin warnings, and side-by-side board comparison.
ESP32 GPIO Pin Mapper
Add sensors and modules, auto-assign free GPIO pins, catch pin conflicts, and export wiring table + Arduino code.