Random Number Generator Online

The online random number generator supports the generation of random integer values and random floating-point values. When unique is specified, all generated random numbers are not repeated.

Stopwatch Online

Online stopwatch timer supports online stopwatch timing, millisecond time, pause, mark and download functions.

Unit Converter Online

Unit converter online supports the conversion of multiple units such as length, weight, area, volume data.

Countdown Timer Online

Countdown timer online supports online countdown. After the countdown, you can set the sound of playing alarm.

Toggle String Case

Character case conversion tool, including character uppercase to lowercase, lowercase to uppercase and case inversion functions.

Datetime Format Converter

Online date time format conversion tool that converts date time into various formats such as ISO, RFC, Unix timestamp, UTC, Excel time, etc. Supports single time conversion and batch time conversion.

Find and Replace Text Online

The online text search and replacement tool uses text or regular expression to find the target text, and then replace it with new content. The replacement content supports text and the back reference of regular expressions.

String Binary Converter

Online string and binary conversion tool, using the selected character set, converts the string to a byte array, and then converts the byte array to a binary string.

China Permanent Residence ID Card Number Query Online

Online permanent residence card number query tool, which can query the province, nationality, date of birth and other information contained in the new version of 18 foreigners' permanent residence ID card number. Batch query is supported.

Greatest Common Divisor and Least Common Multiple Calculator

Online greatest common divisor - least common multiple calculator, input a set of integers of any size, calculate their least common multiple and greatest common divisor.

Text Add Line Number Online

Add line numbers to multi line text online. You can customize the format of adding line numbers, whether they are aligned, and appear at the beginning or end of the line.

CSS Selectors Reference

The CSS selector defines the range of elements that CSS rules apply to. This tool provides a reference manual for CSS universal selectors, type selectors, class selectors, id selectors, combination selectors, attribute selectors, pseudo class selectors, and so on. It also shows the CSS Level that this selector was introduced into.

CIDR Aggregate Online

Online CIDR aggregation calculator, supporting the aggregation of multiple IPs or multiple sub-CIDRs into one CIDR, and supporting both IPv4 and IPv6.

JSON Key Rename Online

Online JSON key renaming tool, supports renaming keys of input JSON data, supports lowerCamelCase,UpperCamelCase,lowercase,UPPERCASE,lower_snake_case,UPPER_SNAKE_CASE,kebab-case, There are various renaming methods such as custom renaming rules. Support adding prefixes or suffixes to keys and setting rules for handling key name conflicts.

Number Sort Online

Online number sorting tool that supports sorting a large number of input numbers and supports multiple ways of inputting or extracting numbers. Supports sorting very large integers and very large floating-point numbers.

ChaCha20 Encrypt and Decrypt Online

Online ChaCha20 Encryption and Decryption Tool, supporting ChaCha20, XChaCha20, ChaCha20-Poly1305, and XChaCha20-Poly1305 algorithms for encryption and decryption, with input data formats including string, hex, and base64, and the ability to select from multiple character sets.

Information Entropy Calculator Online

The online information entropy (Shannon entropy) calculator supports calculating the entropy of binary data, text data, and probability distributions, and supports setting the logarithmic base to 2, e, and 10. Support setting result precision.

Protocol Buffers Encode and Decode Online

Online Protocol Buffer Encoding and Decoding Tool, supporting online decoding of protocol buffer data and online encoding of protocol buffer data. Supports opening multiple proto definition files and decoding and encoding multiple messages.

Geohash Encode Decode Online

Online Geohash encoding and decoding tool, supports Geohash encoding and decoding of latitude and longitude positions, supports querying all coordinate points within a specified radius of the center point, and supports querying the closest coordinate point to the center point.

BaseN Encode and Decode Online

Online BaseN encoding and decoding tool, supporting BaseN encoding and decoding of data such as string, hex, base64, files, etc., supporting algorithms such as base2, base8, base16, base32, base64, base58, base85, base91, base100, etc. This tool also supports custom algorithms.

MessagePack and JSON Converter Online

Online Message Pack and JSON conversion tool, supporting the conversion between binary data in Message Pack format and data in JSON text format. Message Pack data supports input formats such as hex, base64, byte arrays, etc.

Fetal Weight Calculator Online

Online fetal weight calculator predicts and calculates fetal weight based on parameters such as uterine height, abdominal circumference, biparietal diameter, and femur length. Support viewing the distribution of fetal weight, biparietal diameter, abdominal circumference, femur length, and other parameters at different weeks.

ABC Music Notation Editor Online

Online ABC score editor, using ABC notation method to edit scores, supports real-time preview of generated staff, and supports downloading as MIDI and WAV files.

Nano ID Generator Online

Online Nano ID generator, supports batch generation of Nano IDs, supports custom alphabet, and custom Nano ID length.