Converters
Turn one representation into another on this device. Encoding is reversible and is not a cipher. Units use fixed factors, not live FX. Letter case rewrites characters without sending the string anywhere.
68 tools
Categories
Encoding
Open encoding converters for Base64, hex, URL percent-encoding, and HTML entities. If you need a checksum, use hash tools instead.
Units
The unit converter covers length, mass, temperature, volume, area, speed, data, and power. High-volume pairs such as inches to cm and Celsius to Fahrenheit are spokes of that engine.
Text and time
The case converter maps letters. Slugify and camel/snake rewrite identifiers. The time zone converter and world clock use IANA names. Word count lives under tools.
Encoding, units, and text
Color
Date and time
- Date Format Converter ISO, US, EU, RFC 1123, and Unix UTC midnight for a calendar date.
- Meeting Planner One instant in several zones for a meeting.
- Time Zone Converter Interpret the date and time as local in the from zone, then show it in the to zone. DST is the zone database in this browser.
- World Clock Times in selected IANA zones. One page, not a URL per city.
Base64
- Base64 Decoder Decode a Base64 string to UTF-8 text, hex, or another encoding. Invalid input fails with a clear error.
- Base64 Encoder Turn text or encoded bytes into Base64. Pick the input encoding and the alphabet your target system expects.
- Base64 to Hex Base64 to hexadecimal.
- Base64 to Image Preview an image from Base64 or a data URL.
- File to Base64 Any local file to Base64. Does not parse PDF structure.
- Image to Base64 Local image to a Base64 data URL. Nothing uploaded.
Encoding
HTML
- HTML Decoder Replace HTML 4 named character references and decimal or hex numeric references with the characters they stand for. Names are case-sensitive (Ω is not ω). Unknown names are left unchanged.
- HTML Encoder Turn the five HTML text specials into character references so the string can sit in HTML text. Named entities for ampersand, less-than, greater-than, and quotes; numeric ' for apostrophe. Other characters, including emoji, are left as they are.
URL
Numbers
- ASCII Code Converter Characters to code points and back.
- Number Base Converter Convert integers between bases 2 and 36.
- Number to Words Short-scale English cardinal words.
- Roman Numeral Converter Integers 1-3999 to canonical Roman numerals.
- Scientific Notation Converter Scientific and engineering notation.
- Words to Number Parse English cardinal words to an integer.
Text
- Caesar Cipher Toy Caesar cipher. Not for secrets.
- Camel Case to Snake Case Identifier case conversion.
- Case Converter Rewrite letter case in the paste you provide. Unicode letters follow the en-US locale rules in this browser.
- Morse Decoder Morse tokens separated by spaces.
- Morse Encoder International Morse. Space becomes / .
- Newline Converter newline convert in this browser.
- Remove Accents remove diacritics in this browser.
- Reverse Text reverse text in this browser.
- ROT13 ROT13. Symmetric. Not encryption.
- Slug Converter Lowercase, strip diacritics, hyphenate for URLs.
- Unicode Escape \uXXXX and \u{...} escape.
Length
- Centimeters to Inches Centimeters to inches. 1 in = 2.54 cm.
- Feet to Inches Feet to inches. 1 ft = 12 in.
- Feet to Meters Feet to meters. 1 ft = 0.3048 m.
- Height Converter Feet and leftover inches to centimeters, or centimeters to feet and inches. Same inch factor as the length converter.
- Inches to Centimeters One inch is 2.54 centimeters exactly. This page locks those two units on the shared length engine.
- Inches to Millimeters Inches to millimeters.
- Kilometers to Miles Kilometers to statute miles.
- Length Converter Convert a length with SI factors. One inch is 0.0254 meters exactly. For height in feet and inches, use the height page.
- Meters to Feet Meters to feet.
- Millimeters to Inches Millimeters to inches.
Mass
- Grams to Ounces Grams to avoirdupois ounces.
- Kilograms to Pounds The pound is 0.45359237 kg exactly. This page locks kg to lb on the shared mass engine.
- Kilograms to Stone Kilograms to stone. 1 st = 6.35029318 kg.
- Pounds to Kilograms Multiply pounds by 0.45359237. Same mass engine as kilograms to pounds.
- Weight and Mass Converter Avoirdupois pound is 0.45359237 kg. Metric prefixes from the gram. Not a planetary gravity tool.
Power
Temperature
Converter questions
Does a converter upload my text?
No. Conversion runs in the page you opened. CZNull does not receive the input.
Is Base64 encryption?
No. Anyone can decode it. Use it to carry bytes through text systems, not to hide secrets.