iToolHub

All Tools on iToolHub

This is every page on iToolHub, grouped by what the tool converts. Each group opens with the family hub, which explains how that family fits together, and then lists the converters under it. Type in the box to narrow the list.

Number Systems + Character Encoding

Binary, Octal, Decimal, Hex, Text and ASCII.

  • Binary Converterhub One place for every binary conversion: pick a pair and convert binary to decimal, hex, octal, text or ASCII codes.
  • Binary to Decimal Converter Convert a binary number to decimal and see the working: multiply each bit by its power of 2, then add.
  • Decimal to Binary Converter Convert a decimal number to binary by repeated division by 2, reading the remainders from bottom to top.
  • Hex to Decimal Converter Convert hex to decimal: each digit times its power of 16, then summed, so 9C becomes 156.
  • Decimal to Hex Converter Convert decimal to hex by dividing by 16 and reading the remainders upward, so 156 becomes 9C.
  • Hex to Binary Converter Swap every hexadecimal digit for its four bits, no arithmetic needed.
  • Binary to Hex Converter Split a bit string into nibbles of four from the right, padding the left group, then name each nibble with one hexadecimal digit.
  • Binary to Octal Converter Slice the bits into triples from the right and name each triple with one octal digit, 0 through 7.
  • Octal to Binary Converter Write out every octal digit as its three bits and join them.
  • Octal to Decimal Converter Weight each octal digit by a power of 8 and add the products.
  • Decimal to Octal Converter Divide a decimal value by 8 repeatedly and read the remainders upward.
  • Hex to Octal Converter No direct route exists, so pivot through bits: each hexadecimal digit spreads to four, the bits regroup in threes, and the octal digits fall out.
  • Octal to Hex Converter Bits are the bridge: spread each octal digit into three, regroup those bits in fours, and read hexadecimal.
  • Text to Binary Converter Free text to binary translator: type English text and get 8-bit binary code as you type, with each letter worked out.
  • Binary to Text Converter Paste binary code and read it as English text.
  • Text to Hex Converter Encode text as hexadecimal bytes, two hex digits per byte, with multibyte UTF-8 shown in full.
  • Hex to Text Converter Convert hexadecimal bytes into readable text.
  • ASCII Code to Binary Converter Enter ASCII code numbers and read the 8-bit binary for each one.
  • Binary to ASCII Code Converter Read binary bytes as ASCII code numbers: split into 8-bit groups, then take each byte as a value from 0 to 127.
  • Text to ASCII Code Converter Find the ASCII code of any character, written in decimal, hex, octal or binary.
  • ASCII Code to Text Converter Enter ASCII codes in decimal, hex, octal or binary and read the characters back.
  • Hex to ASCII Converter Turn hex bytes such as 48 69 into ASCII text, one character per pair of hex digits from 00 to 7F.
  • Decimal to ASCII Enter decimal codes and read the characters: 0-127 are ASCII, higher values are Unicode code points such as 233 for e-acute.
  • Text to Decimal Converter Get the decimal code point of every character in your text, from 65 for A up to 128512 for an emoji.
  • Text to Octal Converter Write each character as a three-digit octal code, the form used by escape sequences in C and shell strings.
  • Octal to Text Converter Enter three-digit octal codes and read the characters they stand for, escape sequences included.
  • Number System Conversionguide How number systems work and how to move a value between them.
  • Binary Codeguide Binary code writes every value with two digits, 0 and 1.
  • ASCII Tableguide All 128 ASCII codes in one table, each row giving the decimal, hex, octal and binary form plus the character.
  • ASCII vs Unicode vs UTF-8guide ASCII is a 128-code set, Unicode is a code point catalogue, UTF-8 turns code points into bytes.
  • Two's Complementguide Two's complement represents a negative number by inverting the bits and adding one.

Units

Length, Mass, Volume, Energy and More.

  • Unit Converterhub Free unit converter: type a value such as 6 ft to m and read it in every unit of length, mass, volume, temperature, energy or speed, with the factor shown.
  • Electrical Unit Converterhub Convert the electrical quantities together: current, voltage, charge, reactive and apparent power, and reactive energy.
  • Length Converter Convert a length between metric and imperial units, from millimetres to kilometres and inches to miles.
  • Area Converter Area converter calculator online: square metres and feet, acres, hectares and square miles.
  • Volume Converter Volume conversion calculator online: litres, millilitres, cubic units, US and imperial gallons, pints and cups, never mixed.
  • Weight Converter Convert a mass between kilograms, grams, pounds, ounces and stone.
  • Temperature Converter Convert a temperature between Celsius, Fahrenheit and Kelvin.
  • Time Converter Convert a duration between seconds, minutes, hours, days and weeks.
  • Frequency Converter Convert a frequency between hertz and its prefixes, and between hertz and revolutions per minute.
  • Electric Current Converter Move an electric current between amperes and their SI prefixes, microamps up to kiloamps.
  • Voltage Converter Convert a voltage between volts and their SI prefixes, from microvolts to megavolts.
  • Electric Charge Converter Convert an electric charge between coulombs, amp-hours and milliamp-hours, the units printed on batteries.
  • Reactive Power Converter Convert reactive power between volt-amperes reactive and their prefixes.
  • Apparent Power Converter Convert apparent power between volt-amperes, kilovolt-amperes and megavolt-amperes, the rating on a transformer.
  • Reactive Energy Converter Convert reactive energy between volt-ampere-hours reactive and their prefixes, as metered on industrial supplies.
  • Energy Converter Energy conversion calculator for joules, kilowatt-hours, calories, BTU and electronvolts, each calorie and BTU variant named.
  • Power Converter Convert power units online: watts, kilowatts, mechanical and metric horsepower and BTU per hour, with each factor marked exact or rounded and an engine example.
  • Volumetric Flow Rate Converter Convert a volumetric flow rate online: GPM to LPM, litres per second, cubic metres per hour and CFM, with US and UK gallons kept apart and the working shown.
  • Illuminance Converter Convert illuminance between lux, foot-candles and phot.
  • Angle Converter Convert degrees to radians and back, or any angle between degrees, radians, gradians, turns and minutes of arc.
  • Digital Storage Converter Convert digital storage between bits, bytes and their prefixes, with binary KiB and decimal KB kept apart.
  • KB to MB Storage Converter Convert kilobytes to megabytes with both readings shown: divide by 1,000 for SI megabytes, or by 1,024 for the binary MiB that Windows labels MB.
  • MB to KB Storage Converter Turn megabytes into kilobytes.
  • MB to GB Storage Converter Change megabytes into gigabytes and see why 1,024 MB also reads as 1 GB: the decimal answer, the binary GiB answer, and the working for each.
  • GB to MB Storage Converter Convert gigabytes to megabytes.
  • KB to GB Storage Converter Convert kilobytes to gigabytes: 1 GB is 1,000,000 kB in SI units and 1 GiB is 1,048,576 KiB in binary.
  • GB to KB Storage Converter Turn gigabytes into kilobytes without mixing readings: 1 GB is 1,000,000 kB and 1 GiB is 1,048,576 KiB.
  • GB to TB Storage Converter Convert gigabytes to terabytes, decimal and binary side by side, and see why a drive sold as 1 TB appears as about 931 GB when counted in steps of 1,024.
  • TB to GB Storage Converter Convert terabytes to gigabytes.
  • Bits to Bytes Converter Convert bits to bytes by dividing by 8, and see why a 100 Mbps connection moves 12.5 MB per second.
  • Bytes to Bits Converter Convert bytes to bits by multiplying by 8.
  • Speed Converter Convert a speed between kilometres per hour, miles per hour, metres per second and knots.
  • Pace Converter Convert a running pace between minutes per kilometre and minutes per mile, and read the matching speed.
  • Pressure Converter Pressure conversion calculator for pascals, kPa, bar, PSI, atmospheres and mmHg.
  • Torque Unit Converter Convert torque between newton-metres, pound-feet and kilogram-force metres.
  • Parts-Per Converter Convert a concentration between parts per million, parts per billion, parts per trillion and percent.
  • Count Converter Convert a count between each, pairs, dozens, scores, gross and great gross, the units used on order forms.
  • Unit Conversionguide A conversion factor is a ratio equal to one.
  • Megabits vs Megabytesguide A megabyte is eight megabits.
  • MB vs MiBguide A megabyte is 1,000,000 bytes and a mebibyte is 1,048,576.

Image Formats

JPG, PNG, WebP, GIF, BMP and ICO.

Data Formats

JSON, XML, CSV, TSV and Subtitles.

  • Data Format Converterhub Move structured data between serialization formats: JSON, XML, CSV, TSV, plain text and subtitle files.
  • JSON to XML Converter Convert JSON to XML online: keys become elements, arrays become repeated tags and values become text nodes.
  • XML to JSON Converter Convert XML to JSON online and see how attributes, repeated elements and text nodes are written.
  • CSV to JSON Converter Convert CSV to JSON online: the header row becomes the keys, the delimiter is detected, and quoted fields keep their commas.
  • JSON to CSV Converter Convert JSON to CSV online: nested objects become dotted column names, every key gets a column, and the .csv file can carry the byte order mark Excel needs.
  • TSV to JSON Converter Convert tab-separated data to a JSON array of objects, taking the first line as the keys.
  • JSON to TSV Converter Convert a JSON array to tab-separated rows that paste straight into a spreadsheet.
  • JSON to Text Converter Convert JSON to plain text online: each value on its own line, with or without its key, or the whole document as one escaped JSON string.
  • SRT to VTT Converter Convert SRT subtitles to WebVTT online: add the WEBVTT line and turn each timestamp comma into a full stop.
  • VTT to SRT Converter Convert WebVTT to SRT online: drop the header and cue settings, number every cue, and turn the decimal point back into a comma.
  • CSV Fileguide A CSV file is plain text: one record per line, a comma between fields.
  • JSON vs XMLguide JSON holds typed values; XML marks up a tree of named elements.

Text Encodings

HTML Entities, URL Encoding and Base64.

  • Text Encoding Converterhub Encode and decode text three ways: HTML character references, URL percent-encoding and Base64.
  • HTML Encode Escape the characters that break markup, so < becomes &lt; and & becomes &amp;.
  • HTML Decode Decode HTML entities back to text online: named ones such as &amp; and &eacute;, decimal &#65; and hex &#x41;.
  • URL Encode Percent-encode a query value, a whole URL or form data, so a space becomes %20 or +.
  • URL Decode Decode %20 and every other %XX triplet back to UTF-8 text.
  • Base64 Encode Encode text or any file as Base64 in your browser: standard or URL-safe alphabet, padding on or off, MIME lines.
  • Base64 Decode Decode Base64 to text four characters at a time.
  • Image to Base64 Drop, paste or pick an image to get its Base64 data URI plus ready CSS and HTML img lines.
  • Base64 to Image Paste Base64 or a data URI to see the picture and save it with the right extension.
  • URL Encoding vs HTML Encoding vs Base64guide Three encodings, three jobs: percent-encoding protects URLs, entities protect markup, Base64 carries bytes through text channels.

Number Words / Roman Numerals

  • Numeral Converterhub Type a figure, a Roman numeral or number words and get the other two at once.
  • Number to Words Converter Convert numbers to words in British or American style, with cheque (check) wording such as one hundred thirty and 45/100, decimals and any letter case.
  • Words to Number Converter Convert number words to numbers: nine thousand nine hundred and eighty-one is 9981.
  • Number to Roman Numerals Converter Convert numbers and years to Roman numerals from 1 to 3,999: 2026 is MMXXVI and 4 is IV.
  • Roman Numerals to Number Converter Translate Roman numerals to numbers: MCMLXXXVII is 1987 and CM is 900.
  • Roman Numerals Chartguide Every Roman numeral from 1 to 100 with the arithmetic behind it, the forms for each ten, hundred and thousand up to 3,999, and the rules to read any numeral.

Colour Models

HEX, RGB and CMYK.

  • Color Converterhub Type one colour as HEX, RGB or CMYK and get the other two at once, with a colour picker.
  • HEX to RGB Converter Paste a hex colour code such as #1A2B3C and get rgb(26, 43, 60), with a colour picker, the working for each channel, and the 3- and 8-digit forms.
  • RGB to HEX Converter Type RGB values such as 26, 43, 60 or 50% shares and get the hex colour code #1A2B3C, in upper or lower case, with each channel worked as two digits.
  • RGB to CMYK Converter Convert RGB channel values to CMYK ink percentages with the formula, worked step by step.
  • HEX to CMYK Converter Turn a hex colour code into cyan, magenta, yellow and black percentages, reading each pair as a channel first.
  • CMYK to RGB Converter Convert CMYK inks to RGB channels using 255 x (1 - C) x (1 - K), with the unrounded working for red, green and blue and the rounding rule stated.
  • CMYK to HEX Converter Get a hex colour code from CMYK ink values: each channel is worked out from the inks and rounded, then written as two uppercase digits behind a #.
  • RGB vs CMYKguide RGB adds light on a screen; CMYK takes light away with ink on paper.

Calculators, Generators and Downloads

These are not conversions. A calculator works out a new value, a generator invents one, and a downloader fetches a file. None of them takes a value you already have and rewrites it in another form, so they sit apart from the converters and carry the plain "free online" name instead of a converter name.