File Size Checker Action

File Size Checker ensures every newly added file in a pull request stays below a size threshold that you define. Drop it into any workflow to keep oversized binaries or assets from entering your repository.

Quick Start

name: Check File Sizes

on:
  pull_request:
    branches:
      - main

jobs:
  check-size:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Fail if new files are committed over 25KiB
        id: size_check
        uses: pelotech/github-action-file-size-checker@v0.1.2
        with:
          max_file_size_kib: '25'

Inputs

Name	Required	Default	Description
max_file_size_kib	Yes	20	Maximum filesize, in kilobytes, that any newly added file may have.
base_sha	Yes	${{ github.event.pull_request.base.sha }}	Commit SHA used as the lower bound of the diff. Override this if you need to compare against a custom baseline (for example, on push workflows).
head_sha	Yes	${{ github.event.pull_request.head.sha }}	Commit SHA used as the upper bound of the diff. Override when running outside of a pull request.

Tip: When the workflow runs inside a pull request, you can omit base_sha and head_sha because the defaults resolve automatically.

Outputs

• violations_list: Markdown-formatted bullet list describing every new file above the size cap; empty string when no violations occur.
• max_size_human: Human-readable representation of the chosen size limit (for example, 25KiB).

Usage Tips

• Ensure the workflow fetches enough history (actions/checkout with fetch-depth: 0) so both SHAs exist locally.
• The action only inspects files that are newly added between base_sha and head_sha. Updates to existing files are ignored by design.
• If you run the action on push or scheduled workflows, provide valid base_sha/head_sha inputs to control the diff range.
• Custom comparisons: Supply explicit base_sha and head_sha to compare across release branches or long-lived feature branches.
• You can use the outputs with other actions to enhance the workflow when there are violations. For example, to post a PR comment when there are violations:

  - name: Post comment when violations exist
      if: steps.size_check.outputs.violations_list != ''
      uses: peter-evans/create-or-update-comment@v5
      with:
        issue-number: ${{ github.event.pull_request.number }}
        body: |
          ## New File Size Violation Detected
  
          The following files exceed **${{ steps.size_check.outputs.max_size_human }}**:
  
          ${{ steps.size_check.outputs.violations_list }}
  
          Please shrink or remove the files above the limit.