Web Tools
Entropy Calculator
Calculate Shannon entropy, character frequency distribution, and randomness assessment for any text. Supports character-level, byte-level, and bigram analysis modes. Visualize information density and detect patterns. Runs entirely in your browser — your data never leaves your machine.
entropy shannon information randomness frequency analysis
Published May 30, 2026
All interactive tools run entirely in your browser. Your data never leaves your device.
How It Works
Enter text and see its Shannon entropy calculated in real time. The tool measures information density by analyzing character frequency distribution, showing how much randomness or structure exists in the data.
Analysis Modes
- Character-level: analyze individual characters (default)
- Byte-level: analyze raw UTF-8 bytes
- Bigram-level: analyze consecutive character pairs
Features
- Shannon entropy: calculated in bits per symbol
- Maximum entropy: theoretical maximum for the character set
- Entropy ratio: percentage of maximum possible entropy
- Randomness assessment: 5 levels from very low to very high with color indicators
- Frequency distribution: visual bars showing character counts and probabilities
- Self-information: bits of information per symbol
- 5 examples: repeated text, English, random hex, binary, password
- Private: runs entirely in the browser — no data transmitted
Use Cases
- Assessing password strength and randomness
- Analyzing data compression potential
- Detecting patterns in encoded or encrypted data
- Measuring information content in text for NLP tasks
- Evaluating random number generator output quality