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Technology

GitHub Actions

Difficulty

Beginner

Experience

Fresher

Type

Technical

AutomateQA Team

QA Automation Engineers

June 20, 2026

Interview Question

What are GitHub Actions runners? What is the difference between GitHub-hosted and self-hosted runners?

Q: What are GitHub Actions runners? What is the difference between GitHub-hosted and self-hosted runners?

GitHub Actions Runners A runner is the machine (VM or container) that executes the steps in a job. Every job gets a fresh runner by default. GitHub-Hosted Runners Managed by GitHub — free for public repos, 2000 min/month for private. yaml jobs: build: runs-on: ubuntu-latest Latest Ubuntu LTS or: runs-on: ubuntu-22.04 Specific Ubuntu version runs-on: windows-latest Windows Server runs-on: windows-2022 runs-on: macos-latest macOS (most expensive minutes) runs-on: macos-14 What's Pre-installed on ubuntu-latest yaml - Java (multiple versions via setup-java) - Node.js (multiple versions) - Python 3

Answer

GitHub Actions Runners

A runner is the machine (VM or container) that executes the steps in a job. Every job gets a fresh runner by default.

GitHub-Hosted Runners

Managed by GitHub — free for public repos, 2000 min/month for private.

YAML

jobs:
  build:
    runs-on: ubuntu-latest      # Latest Ubuntu LTS
    # or:
    runs-on: ubuntu-22.04       # Specific Ubuntu version
    runs-on: windows-latest     # Windows Server
    runs-on: windows-2022
    runs-on: macos-latest       # macOS (most expensive minutes)
    runs-on: macos-14

What's Pre-installed on ubuntu-latest

YAML

- Java (multiple versions via setup-java)
- Node.js (multiple versions)
- Python 3.x
- Maven, Gradle
- Docker
- Chrome, Firefox (for headless Selenium/Cypress)
- git, curl, wget, jq
- AWS CLI, Azure CLI, GCP SDK

Check Installed Software

YAML

steps:
  - run: java -version
  - run: mvn -version
  - run: node --version
  - run: google-chrome --version
  - run: docker --version

Self-Hosted Runners

Your own machine registered with GitHub. Used when you need:

✓Access to private network / internal services
✓Specific hardware (GPU, arm64)
✓Custom pre-installed tools
✓High usage (cost savings vs GitHub-hosted minutes)

Register a Self-Hosted Runner

Bash

# 1. Go to: Repo → Settings → Actions → Runners → New self-hosted runner
# 2. Choose OS, download runner package
# 3. Configure and start:

./config.sh --url https://github.com/org/repo --token YOUR_TOKEN
./run.sh   # starts the runner (or install as service)

Use Self-Hosted Runner in Workflow

YAML

jobs:
  test:
    runs-on: self-hosted           # any self-hosted runner
    # or with labels:
    runs-on: [self-hosted, linux, selenium]   # runner with these labels
    runs-on: [self-hosted, windows, gpu]

Label Your Runners

Bash

# Add labels when registering
./config.sh --url ... --token ... --labels "linux,selenium,chrome"

Comparison

	GitHub-Hosted	Self-Hosted
Setup	Zero	Install runner agent
Cost	Free (public) / Minutes (private)	Infrastructure cost
Maintenance	GitHub manages	You manage OS, updates
Network	Public internet only	Access internal systems
Hardware	Fixed (2 CPU, 7GB RAM)	Your spec
Security	Ephemeral (fresh each job)	Persistent — careful with secrets
Best for	Most projects	Private network, custom env

Docker Container Runner

YAML

jobs:
  test:
    runs-on: ubuntu-latest
    container:
      image: maven:3.9-openjdk-17   # run job inside this container
      options: --user root
    steps:
      - uses: actions/checkout@v4
      - run: mvn test  # runs inside Maven container