24 recent additions
New tools
The newest entries in the catalog, newest first. Each one ships with a working implementation, documentation and an FAQ — nothing here is a placeholder.
BMR and Calorie Calculator
Basal metabolic rate and daily calorie needs.
CMYK to HEX and RGB Converter
Convert between CMYK, HEX and RGB colour values.
Colour Name Finder
Find the closest CSS colour name to any shade.
Electricity Cost Calculator
What an appliance costs to run per day, month and year.
Fancy Text Generator
Bold, italic, script and other Unicode styles to copy.
Fraction Calculator
Add, subtract, multiply and divide fractions.
GCD and LCM Calculator
Greatest common divisor and least common multiple.
HTML to Markdown Converter
Convert HTML into clean Markdown.
HTTP Status Codes Reference
Look up what any HTTP status code means.
IP Subnet Calculator (CIDR)
Network, broadcast, mask and host range of an IPv4 subnet.
JSON String Escape and Unescape
Escape text for a JSON string, or read an escaped one.
JSON to TypeScript Interface Generator
Generate TypeScript interfaces from a JSON sample.
Prime Factorization Calculator
Check if a number is prime and find its factors.
Readability Score Checker
Flesch reading ease for English and French text.
Remove Accents from Text
Strip diacritics: é becomes e, ç becomes c.
Rule of Three Calculator
Solve a proportion: if A gives B, what does C give?
Running Pace Calculator
Pace per km and per mile from distance and time.
Speed, Distance and Time Calculator
Find speed, distance or travel time from the other two.
User Agent Parser
Identify the browser, OS and device from a user agent.
Word Wrap Text
Wrap long lines at a fixed number of characters.
Add Line Numbers
Number every line of a text or code listing.
Add or Subtract Days from a Date
Find the date a number of days, weeks or months away.
BMI Calculator
Body mass index from height and weight, metric or imperial.
CSV to Markdown Table
Turn spreadsheet data into a Markdown table.