FM Workbench – Online Developer & Embedded Tools

Small tools. Big time savings.

FM Workbench is a curated collection of fast, privacy-friendly online tools for software, firmware, and hardware engineering tasks. All tools run locally in your browser with no tracking or signup. Popular tools include SMD Resistor Code, JSON Formatter, What Is My IP, ASCII Table, Image Converter, I2C Pull-up Calculator, and CRC Calculator.

General JSON Formatter format • validate • minify General Text Counter chars • bytes • lines General Base64 / URL Encode·Decode encode • decode General Query String Parser url params • decode • query to json General Unix Timestamp Converter epoch • UTC General UUID GeneratorNEW v1 • v4 • v7 • bulk General Regex TesterNEW live match • capture groups • cheat sheet General Hash GeneratorNEW MD5 • SHA-1 • SHA-256 • SHA-512 General Diff ViewerNEW text diff • hex compare • Myers algorithm General What Is My IP public IP • Cloudflare General Image Converter png to jpg • webp to png • format guide General PNG to JPG Converter photo optimization • quality tradeoff General WEBP to PNG Converter compatibility • transparency workflow Firmware IEEE-754 Converter hex ↔ float/double Firmware UART Packet Time baud • frame • transfer time Firmware UART Baud Error Calculator clock • divider • baud mismatch Firmware UART 115200 Error Guide popular baud rate • quick mismatch check Firmware UART 8N1 Calculator 10 bits/byte • quick timing Firmware Hex to Float Converter ieee-754 decode • endian Firmware HEX ⇄ ASCII ⇄ Binary dump • parse • endian Firmware CRC Calculator CRC8 • CRC16 • CRC32 Firmware Checksum Calculator XOR • SUM • LRC Firmware Struct Layout offset • padding • pack Firmware ASCII TableNEW 0–255 chart • DEC HEX OCT BIN • search & filter Firmware Endian ConverterNEW byte swap • big ↔ little endian • 8/16/32/64-bit Hardware Color Picker rgb 0-255 • hex • 0xrrggbb • rgb565 Hardware Color Code Converter hex ↔ rgb ↔ 0xrrggbb ↔ rgb565 Hardware RGB565 to HEX Converter 16-bit color decode • embedded display Hardware LED Resistor Calculator series resistor • power rating Hardware LED Resistor 12V Guide 12v examples • part selection Hardware SMD Resistor Code 103 • 4R7 • EIA-96 Hardware Voltage Divider Vout • current • power Hardware I2C Pull-up Resistor Calculator rmin/rmax • rise time • bus capacitance Hardware I2C Pull-up 3.3V Guide 3.3v bus • practical resistor starting points Hardware Ohm's Law CalculatorNEW V = IR • power • formula reference Hardware Timer Prescaler CalculatorNEW PSC • ARR • MCU timer frequency • error % Hardware Capacitor Code ConverterNEW 3-digit code • pF • nF • µF • tolerance
Tip: Bookmark this page and use the category links above. New tools will appear here as they ship. Ctrl + D