How to add a signature in Gmail (and keep the formatting)

Gmail lets you paste a fully formatted signature into its settings. Most problems come from how the signature was copied, not from Gmail itself. Here is the whole process, start to finish.

Before you start

You need a signature that was built for email: table-based layout, inline styles and images hosted on a public HTTPS address. Signatures designed in a word processor or as a single image tend to break. If you made yours in Sendoff, it already meets these rules.

Copy the signature as formatted content, not as code. In Sendoff, that is the “Copy signature” button. It puts a rich-text version on your clipboard that Gmail understands.

Add the signature

1. Open Gmail on a computer and click the gear icon, then See all settings.
2. Stay on the General tab and scroll to Signature.
3. Click Create new, give it a name such as “Work”, and click inside the empty box.
4. Paste with Ctrl+V (Windows) or Cmd+V (Mac).
5. Under Signature defaults, choose the new signature for new emails and for replies and forwards.
6. Scroll to the bottom and click Save Changes.

Send a test email to another address you own and look at it there. The settings box is a rough preview; the received message is what matters.

If the formatting disappears

• You pasted plain text. Some browsers drop formatting when the clipboard is accessed from another tab. Copy again and paste immediately.
• Images show as broken icons. Gmail fetches images through its own proxy, so they must be publicly reachable. Images on an intranet, behind a login or embedded as base64 data will not load.
• Gmail says the signature is too long. The limit is 10,000 characters of HTML. Remove an extra banner or a long disclaimer, or use a simpler template.

The Gmail mobile apps

The Gmail apps for Android and iPhone have their own, plain-text Mobile signature setting. If it is filled in, it replaces your formatted signature on messages sent from the app. Open the app’s settings, choose your account and clear the mobile signature. Gmail then adds your web signature to messages you send from your phone.

For a whole company

If you manage Google Workspace for a team, you do not have to repeat this for every person. Sendoff can write each person’s signature into their Gmail settings through the Gmail API, including aliases, and update everyone when the template changes.