GitHub Codespaces

Overview

GitHub Codespaces is a cloud development environment attached to a repository or template. Each codespace is a Docker container built from the repo's devcontainer.json (or a default Ubuntu image) that runs on "its own newly-built virtual machine" with its own virtual network, so isolation is at the VM level. You open it in the browser, VS Code or over SSH, and create or control it from the web UI, the gh codespace CLI (create, ssh, stop, delete, ports, cp) or the REST API (POST /repos/{owner}/{repo}/codespaces, start, stop, delete). Machine types run from 2 cores / 8 GB / 32 GB to 32 cores / 128 GB / 128 GB.

Lifecycle is designed around humans: a codespace stops after 30 minutes idle by default, has a hard 12-hour maximum lifetime per session, and stopped codespaces are retained for 30 days before deletion. Saved files persist across stops. Billing is per core-hour ($0.18/hour for 2 cores) plus $0.07 per GB-month of storage, with free monthly quotas for personal accounts. There is no snapshot or fork API, no GPU and no documented startup figure. GitHub's Copilot coding agent uses separate infrastructure and is not covered here.

Notable

• Personal GitHub Free accounts include 120 core-hours and 15 GB-month of Codespaces usage per month; Pro includes 180 core-hours and 20 GB-month.
• Hard limits: 12-hour maximum active lifetime, 30-minute default idle timeout, 30-day default retention.
• Compute is billed per core at $0.09 per core-hour (2-core $0.18/hour up to 32-core $2.88/hour).

GitHub Codespaces specifications

Facts from GitHub Codespaces’s public documentation, verified November 9, 2026. Performance numbers are vendor claims.

Strengths and trade-offs

Strengths

• You want repo-linked Dev Container workspaces on dedicated VMs with a REST API and CLI
• You need per-user isolation, private port forwarding and GitHub secrets without running infrastructure
• You are a personal account that can use the free monthly core-hour quota

Trade-offs

• 12-hour maximum session and human-oriented idle/retention policies rather than an agent lifecycle
• No snapshot, fork or pause-with-memory APIs; no GPU machine types
• Cannot run on your own cloud; organisations pay for every core-hour with no included quota

Good fit for: Developer-driven workspaces tied to GitHub repositories, where an agent assists a human inside a Dev Container.

Use cases GitHub Codespaces fits

• Coding agents: Dev Container workspaces tied to GitHub repositories, one VM per codespace with prebuilds and port forwarding, where an agent works alongside a developer.

How GitHub Codespaces compares

See all GitHub Codespaces alternatives →

Frequently asked questions

Sources

1. docs.github.com/en/codespaces/about-codespaces/what-are-codespaces
2. docs.github.com/en/codespaces/about-codespaces/the-codespace-lifecycle
3. docs.github.com/en/codespaces/reference/security-in-github-codespaces
4. docs.github.com/en/billing/managing-billing-for-your-products/managing-billing-for-github-codespaces/about-billing-for-github-codespaces
5. docs.github.com/en/codespaces/setting-your-user-preferences/setting-your-default-region-for-github-codespaces
6. docs.github.com/en/rest/codespaces/codespaces
7. docs.github.com/en/codespaces/developing-in-a-codespace/using-github-codespaces-with-github-cli