# Duplicate file finder

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

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `duplicate-file-finder` |
| 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

Files are read locally in bounded chunks and never changed. Only selected files are inspected. Cancel at any time.

### Inputs and settings

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

Accepted browser files: `See implementation notes`. Multiple files are supported.

Browser file-input limit: 536870912 bytes in total. HTTP limits can differ.

No additional settings are declared for this tool.

### 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

Up to 2,000 files, 512 MiB total and 256 MiB per file. Matching hashes are checked with a direct byte comparison. Very large comparison workloads are bounded and may require a smaller folder. Nothing is deleted.

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

### Complete machine-readable capability record

```json
{
  "id": "duplicate-file-finder",
  "category": "developer-tools",
  "built": true,
  "requirements": "Up to 2,000 files, 512 MiB total and 256 MiB per file. Matching hashes are checked with a direct byte comparison. Very large comparison workloads are bounded and may require a smaller folder. Nothing is deleted.",
  "implementation": {
    "fields": [],
    "files": true,
    "input": false,
    "directory": true,
    "multiple": true,
    "deferImagePreview": true,
    "presentation": "metrics",
    "maxFileBytes": 536870912,
    "uploadHelp": "Choose one folder, up to 2,000 files and 512 MiB total; 256 MiB per file.",
    "note": "Files are read locally in bounded chunks and never changed. Only selected files are inspected. Cancel at any time.",
    "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

Find byte-identical files by size, SHA-256 and a final direct byte comparison.

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 Duplicate file finder

1. Choose the folder you want to inspect.
2. Review the options and run the check.
3. Read the result and download the report.

## Useful next steps

- [Filename portability checker](https://happytails.ai/en/developer-tools/filename-portability-checker/) ([Markdown](https://happytails.ai/en/developer-tools/filename-portability-checker.md))

- [Long path checker](https://happytails.ai/en/developer-tools/long-path-checker/) ([Markdown](https://happytails.ai/en/developer-tools/long-path-checker.md))

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

## Choose one local folder

Use the folder picker and confirm the files you want to inspect. Nested paths are preserved. Choosing another folder replaces the selection.

### Review the result

Find byte-identical files by size, SHA-256 and a final direct byte comparison.

### Download your report

Save the report or manifest to keep the results. Your source files are unchanged, and the processing stays in your browser.