Report Format Reference

Set with -rf/--report-format; see How to Choose a Report Format for task-oriented guidance on choosing one.

Format	Value	Extension	Includes warnings?
Markdown	markdown	.md	No (errors only)
JSON	json	.json	Yes
GitHub annotations	github-annotations	.txt	Yes
Console	console	.txt	Yes

Markdown (default)

A per-check header (e.g. “Check Broken URLs”), an optional line linking to --guide-url, and an HTML table of error-level issues only with columns: file path, link, line number. This is the format the action-check-markdown action posts as a pull request comment.

JSON

A structured document including both errors and warnings:

{
  "tool": {"name": "markdown-checker", "version": "1.2.0"},
  "check": "check_broken_urls",
  "summary": {
    "files_checked": 10,
    "links_checked": 42,
    "errors": 1,
    "warnings": 2
  },
  "files": [
    {
      "path": "docs/index.md",
      "issues": [
        {
          "link": "https://example.com/gone",
          "line": 8,
          "level": "error",
          "message": "is broken"
        }
      ]
    }
  ]
}

GitHub annotations

One line per issue (errors and warnings), in the format GitHub Actions recognises as a workflow annotation:

::error file=docs/index.md,line=8::File docs/index.md, line 8, Link https://example.com/gone is broken.
::warning file=docs/index.md,line=12::File docs/index.md, line 12, Link https://example.com/api was skipped due to rate limiting.

Console

Plain, human-readable text blocks - one per issue, errors and warnings both included:

File '/abs/path/docs/index.md', line 8
https://example.com/gone is broken.

This is also what’s printed to the terminal automatically in local (non-CI) mode, independent of --report-format.