Course 01 — Git, by doing

Learn Gitby actually using it.

A course you type rather than read. Every lesson drops you into a live repository with a real terminal — make a commit and watch it appear, rebase and watch your work replay onto a new base, push and watch it reach the server. From your first commit to rewriting shared history safely.

Start lesson one Open the sandbox

33 lessons · 7 chapters · free

Git — a rebase, then a fast-forward
  1. 01 · Read

    Each lesson is one idea, explained in a few short paragraphs — no walls of theory.

  2. 02 · Do

    Type into a live environment and watch it react. Tab completes, ↑ recalls, undo takes back any step.

  3. 03 · Match

    Reach the goal any way you like — you're judged on the result, not the keystrokes. Par is the shortest route.

01

Snapshots

The working directory, the staging area and the commit — what Git actually saves, and when.

  1. 01 Your first commit The three places a change lives, and how one becomes a commit.
  2. 02 Stage only what belongs together One commit, one idea — choosing what goes into a snapshot.
  3. 03 Take it back with restore Unstage a file, or throw away a change entirely.
  4. 04 History is a chain Every commit points at its parent. That's the whole data structure.
02

Branching

Branches are cheap pointers. Make them, switch between them, and bring their work back together.

  1. 05 A branch is just a pointer Create a branch, switch to it, and watch it move as you commit.
  2. 06 Diverge on purpose Two lines of work from the same starting point.
  3. 07 Bring work together with merge A merge commit has two parents — and that's how it joins histories.
  4. 08 When a merge just moves a pointer Fast-forward merges, and cleaning up a merged branch.
03

Moving around

HEAD, detached HEAD, relative refs and tags — how to point at any commit in history.

  1. 09 HEAD, and detaching it Check out any commit — and understand the warning Git gives you.
  2. 10 Relative refs: ^ and ~ Point at commits by position instead of copying hashes.
  3. 11 Move a branch by force Point a branch at any commit you like.
  4. 12 Tags mark moments A label that never moves — for releases.
04

Undoing

Reset, revert, the reflog and the stash. Almost nothing in Git is truly lost.

  1. 13 Rewind with reset Move your branch back in time — locally.
  2. 14 Uncommit, but keep the work reset --soft: undo the commit, keep everything staged.
  3. 15 Undo in public with revert Undo a commit without rewriting history anyone else has.
  4. 16 The reflog remembers Recover from a reset you regret.
  5. 17 A pocket for unfinished work Stash your changes, fix something urgent, and pick up where you left off.
05

Rewriting history

Rebase, cherry-pick, amend and interactive rebase — shaping history before you share it.

  1. 18 Rebase: replay your work Move a branch so it starts from the latest main.
  2. 19 Rebase, then fast-forward The linear-history workflow, end to end.
  3. 20 Cherry-pick exactly what you need Copy individual commits from anywhere onto where you are.
  4. 21 Fix the last commit --amend replaces your latest commit.
  5. 22 Clean up with interactive rebase Reorder, squash and drop commits before you share them.
06

Working with others

Clone, fetch, pull and push — and what to do when the server says no.

  1. 23 Clone: your own full copy Download a repository — all of its history, not just the files.
  2. 24 origin/main is a bookmark Remote-tracking branches only move when you talk to the server.
  3. 25 Fetch: see what changed Download new work without touching yours — then merge it.
  4. 26 Pull = fetch + merge One command to bring in other people's work.
  5. 27 Push: publish your commits Send your work to the server.
  6. 28 When push is rejected Someone pushed first. Integrate their work, then push yours.
  7. 29 Share a feature branch Push a new branch and set its upstream.
07

Mastery

Transplanting branches, shipping hotfixes, force-pushing safely and recovering deleted work.

  1. 30 Transplant with --onto Move a branch off one base and onto another.
  2. 31 Ship a hotfix to two lines One fix, applied to main and to an older release.
  3. 32 Rewrite a pushed branch safely Rebase a published branch, then force-push without clobbering anyone.
  4. 33 Recover a deleted branch Branch -D isn't the end. The reflog is.

The simulator models commits, branches, HEAD, the reflog, a remote, and the working tree, staging area and stash. It doesn't model file contents, so there are no merge conflicts here — when you meet one for real, the mental model you build here is what gets you through it.