Git: Authentication Failed When Pushing to GitHub

You push and get:

remote: Support for password authentication was removed.
fatal: Authentication failed for 'https://github.com/you/repo.git/'

Your password isn't wrong — it just isn't accepted anymore. GitHub removed password authentication for Git operations over HTTPS back in 2021. You now authenticate with either a personal access token (PAT) or an SSH key. Pick one.

Option A: Personal access token (stays on HTTPS)

Fastest if your remote is already an https:// URL.

1. On GitHub: Settings → Developer settings → Personal access tokens → Fine-grained tokens → Generate new token.
2. Give it repo (or fine-grained "Contents: read/write") access to the repo, set an expiry, and copy the token — you only see it once.
3. Push again. When Git prompts for a password, paste the token instead:

git push
# Username: your-github-username
# Password: <paste the token, not your account password>

So you don't paste it every time, let Git remember it:

git config --global credential.helper store   # or 'osxkeychain' / 'manager'

The token is the password now. Treat it like one: give it the narrowest scope that works and an expiry date, and never commit it into a repo.

Option B: SSH key (no tokens to manage)

Better long-term if you push often.

ssh-keygen -t ed25519 -C "[email protected]"   # press Enter for defaults
cat ~/.ssh/id_ed25519.pub                     # copy this public key

Add that public key on GitHub under Settings → SSH and GPG keys, then switch your remote from HTTPS to SSH:

git remote set-url origin [email protected]:you/repo.git
ssh -T [email protected]        # test: should greet you by username
git push

The checklist

1. The error means password auth is gone — not a typo.
2. HTTPS remote → create a PAT, paste it as the password, cache with a credential helper.
3. Push a lot → generate an SSH key, add the public key, switch the remote to git@.
4. Never commit a token; scope and expire it.