Automatically label your Pull Requests with size indicators -- XS, S, M, L, XL -- based on the total number of lines changed.

Helps teams quickly triage PRs, encourage smaller changes, and keep code review manageable.

When a Pull Request is opened or updated, this action:

1. Fetches the PR diff stats (additions + deletions).
2. Calculates the total number of changed lines.
3. Applies a size/* label based on configurable thresholds.
4. Removes any previously applied size label so only one is present at a time.
5. Posts (or updates) a comment with a breakdown of the changes.

Labels are created automatically in your repository with a color gradient from green (XS) to red (XL).

Add the following workflow file to your repository at .github/workflows/pr-size.yml:

name: PR Size Labeler

on:
  pull_request:
    types: [opened, synchronize, reopened]

permissions:
  contents: read
  pull-requests: write
  issues: write

jobs:
  label:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: tatelyman/pr-size-labeler@v1
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}

      - uses: tatelyman/pr-size-labeler@v1
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          xs_max: "5"
          s_max: "25"
          m_max: "100"
          l_max: "300"

Anything above l_max is labeled XL.

When the action runs, it posts a comment like this:

size/M Pull Request

Metric	Count
Additions	+120
Deletions	-45
Total changes	165

The action creates color-coded labels automatically:

• size/XS -- green
• size/S -- yellow-green
• size/M -- yellow
• size/L -- orange
• size/XL -- red

The action needs the following permissions:

• pull-requests: write -- to add labels and post comments
• contents: read -- to access PR diff stats

These are configured in the workflow YAML as shown in the usage example above.

MIT

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