Code Heatmap Formatter🔒 100% local

Visualize code execution frequency. Privacy-first, no server uploads, no tracking.

Input

Code Heatmap Formatter: related tools

Border Radius Preview Box Shadow Generator Code Sanitizer

Scores pasted code line by line: each branch keyword adds 2, indentation depth and bracket count add 1 each, every 40 characters adds 1, and a recognised function signature subtracts 1. The scores are scaled against the worst line and drawn as a three-character block ramp next to the line number, with branchy and long lines flagged on the right. Under the map it reports code/comment/blank counts, an estimated cyclomatic complexity, the deepest indent, a maintainability score out of 100 and the five lines to look at first.

Code Heatmap: how to use it

Paste the function or file into the box.
Press Process.
Work down the hot-spot list at the bottom of the report; it repeats the highest-scoring lines with their numbers.

Code Heatmap: worked example

function f(x) {
  if (x) return 1;
}

becomes

Heatmap legend:    . : - = + * # % @   (light → heavy)

     1  :::  function f(x) {
     2  @@@    if (x) return 1;
     3       }

Summary:
  Lines:            3  (3 code, 0 comment, 0 blank)
  Comment ratio:    0%
  Cyclomatic (est): 2   (simple)
  Max indent depth: 1
  Branchy lines:    0
  Long lines:       0   (>120 chars)
  Maintainability:  96/100

Hot spots (fix these first):
  line    2  score   4   if (x) return 1;
  line    1  score   1   function f(x) {

How the score is computed: 2 per branch keyword, +1 per indent level, +1 per 40 chars, +1 per bracket, -1 for a function signature.
Rule of thumb: a function above cyclomatic 10 is hard to test; above 20 it is hard to reason about. Extract branches into named helpers.

The bar is relative: line 2 is the heaviest line here, so it gets the darkest symbol, and its indent and bracket count give it a score of 4.

Code Heatmap: when to use it

Finding the gnarly function in a file before you start a refactor.
Getting a rough complexity number for a code review comment without installing a linter.
Checking whether a function you just wrote crept over a comfortable branch count.

Code Heatmap: what it does not do

The scoring is regex-based, so it counts words that look like branches; "and" and "or" inside a string or a comment-free prose line can raise a score.
The cyclomatic figure is a count of decision keywords plus one, not a real control-flow graph, and it will disagree with a compiler-based tool.
Scores are relative to the heaviest line you pasted, so the same line can change shade between two runs with different inputs.
Indent depth is computed as two spaces per level, so tab-indented code reads as depth 0.
One file per paste; there is no repository or multi-file analysis.

✨Code Heatmap Formatter🔒 100% local