# File entropy visualizer

- Human page: https://happytails.ai/en/developer-tools/file-entropy-visualizer/
- Markdown: https://happytails.ai/en/developer-tools/file-entropy-visualizer.md
- Structured JSON: https://happytails.ai/agents/en/developer-tools/file-entropy-visualizer/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `file-entropy-visualizer` |
| Category | developer-tools |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Use the visible action or interactive controls. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Plot Shannon entropy in bits per byte using non-overlapping windows. Maximum 4,096 windows and 256 MiB. High entropy does not prove encryption or compression.

### Inputs and settings

No free-text input is required. Use the file inputs and/or settings below.

Accepted browser files: `See implementation notes`. Choose one file.

Browser file-input limit: 268435456 bytes in total. HTTP limits can differ.

| Setting | Meaning | Control type | Default | Constraints |
| --- | --- | --- | --- | --- |
| `blockSize` | Bytes per window | number | 65536 | min=256 max=1048576 step=1 |

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

One file up to 256 MiB, using windows of 256–1,048,576 bytes and at most 4,096 windows. Entropy ranges from 0 to 8 bits per byte. Short windows have sampling limits; high entropy does not prove encryption or compression.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "file-entropy-visualizer",
  "category": "developer-tools",
  "built": true,
  "requirements": "One file up to 256 MiB, using windows of 256–1,048,576 bytes and at most 4,096 windows. Entropy ranges from 0 to 8 bits per byte. Short windows have sampling limits; high entropy does not prove encryption or compression.",
  "implementation": {
    "fields": [
      {
        "key": "blockSize",
        "label": "Bytes per window",
        "value": 65536,
        "type": "number",
        "min": 256,
        "max": 1048576,
        "step": 1
      }
    ],
    "files": true,
    "input": false,
    "multiple": false,
    "maxFileBytes": 268435456,
    "presentation": "metrics",
    "deferImagePreview": true,
    "note": "Plot Shannon entropy in bits per byte using non-overlapping windows. Maximum 4,096 windows and 256 MiB. High entropy does not prove encryption or compression.",
    "experience": {
      "automatic": false,
      "single": false,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Up to 1,000,000 characters. Review the settings before running.",
      "action": null
    },
    "mode": "explicit",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Plot Shannon byte entropy across a local file and inspect each window’s measured value.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

### How to use File entropy visualizer

1. Choose the local file or files.
2. Review the action and limits, then run the inspection.
3. Check the result and download a separate output or report.

## Useful next steps

- [Byte order mark editor](https://happytails.ai/en/developer-tools/byte-order-mark-editor/) ([Markdown](https://happytails.ai/en/developer-tools/byte-order-mark-editor.md))

- [Line ending auditor](https://happytails.ai/en/developer-tools/line-ending-auditor/) ([Markdown](https://happytails.ai/en/developer-tools/line-ending-auditor.md))

- [File hash](https://happytails.ai/en/developer-tools/file-hash/) ([Markdown](https://happytails.ai/en/developer-tools/file-hash.md))

## Choose a window size

Smaller non-overlapping windows reveal local changes; larger windows reduce sampling variation. A final partial window is included.

### Read the measured profile

The chart plots each window at its midpoint. Constant bytes have zero entropy; a uniform distribution of all 256 byte values has eight bits per byte.

### Download the evidence

Save the SVG chart, per-window CSV or JSON including the full byte histogram. Interpret the pattern as a measurement, not a file-type or security verdict.