Recovering lost commits and branches with the reflog

Goal

Get back commits that seem to have vanished after git reset --hard, a rebase that went wrong, git commit --amend or a deleted branch, without guessing object IDs.

Prerequisites

The work was committed (or at least staged) at some point in this repository. The reflog is local: it records when the tips of branches and other references were updated in this clone, as the git-reflog documentation states. Garbage collection has not expired the entries yet; the documented defaults are 90 days (gc.reflogExpire) and 30 days for entries no longer reachable from the branch tip (gc.reflogExpireUnreachable).

Steps

1. Stop changing things. Do not run git gc, git prune or git reflog expire until the recovery is done.
2. Run git reflog for HEAD, or git reflog show <branch> for one branch. Each line reads HEAD@{n}: <action>: <message>; HEAD@{2} means the second prior value of HEAD, and main@{yesterday} is also valid (gitrevisions documents both the ordinal and the date form).
3. Find the entry just before the damaging action by its label: reset:, rebase (start), commit (amend), checkout:.
4. Inspect before touching anything: git show HEAD@{3}, git log --oneline -5 HEAD@{3}, git diff HEAD HEAD@{3} --stat.
5. Put a branch on the old position first: git branch rescue HEAD@{3}. Then merge, cherry-pick or git reset --hard rescue from a known-good state.
6. For a deleted branch, its own reflog is gone, but HEAD's reflog still lists the commits and checkouts made on it; search with git reflog | grep <keyword>.
7. If nothing in the reflog matches (for example after git stash clear), run git fsck --lost-found; it writes dangling commits into .git/lost-found/commit/ and, for dangling blobs, the contents themselves into .git/lost-found/other/. Staged-but-uncommitted file versions can sometimes be found this way.

Expected result

The lost commits are reachable from a named branch again, and the recovery leaves the current branch untouched until you decide how to combine the two.

Limits and test basis

The reflog never contains working-tree changes that were neither committed nor staged; those are gone. A fresh clone has an empty reflog, and a colleague cannot recover your loss from theirs. Entries survive only until expiry or an explicit git reflog expire. Behaviour follows the cited documentation; no timings are claimed.