Character Frequency Heatmap
Visualize character frequency in text.
Overview
Paste in any block of text and the heatmap shows which characters appear most often, color-graded from cold (rare) to hot (very common). It covers every distinct character in your input — letters, digits, punctuation, whitespace, and even invisible Unicode points.
Linguists profiling a corpus, cryptanalysts attacking a substitution cipher, content marketers checking keyword density, and developers spot-checking encoding issues all use a character frequency visualization. It's also a quick way to confirm that a "long" string isn't secretly half spaces.
How it works
The tool tallies each character in your input, then sorts the results by count. Each row gets a colored background whose intensity scales with that character's relative frequency, using a linear or log-scale gradient. Case sensitivity, whitespace inclusion, and Unicode normalization are usually toggleable so you can compare apples to apples.
Examples
Input: the quick brown fox
Heatmap (top entries):
' ' 3 ███████
'o' 2 █████
'h' 1 ███
...
Input: AAABBC
Heatmap:
'A' 3 ███████
'B' 2 █████
'C' 1 ███
FAQ
Does it count uppercase and lowercase separately?
By default, yes. Most modes offer a case-insensitive toggle so "A" and "a" share a row.
Is whitespace included?
Spaces, tabs, and newlines are counted by default with a marker like 'SPACE' or '⏎' so you can see them. Toggle whitespace off to focus on visible characters.
Why use log scale?
Natural language is heavily skewed — in English, "e" dwarfs "z". Log scale prevents the most common characters from squashing the visualization of everything else.