You can add or change your Gmail signature in the Android app from the app's Settings screen. You choose which Google account the signature is for as part of the steps. This guide covers Android only, because that is the version of Google's instructions we could confirm. The desktop and iPhone steps are not covered here.
What a Gmail signature does
Google's Gmail Help page describes a signature as text, such as your contact information or a favourite quote, that Gmail automatically adds as a footer at the end of your messages. You write it once and Gmail adds it for you.
Steps to add or change a signature on Android
These steps come from Google's Android instructions. The same steps work whether you are adding a signature for the first time or editing one you already have.
- Open the Gmail app.
- At the top left, tap Menu.
- Scroll to the bottom and tap Settings.
- Choose the Google Account where you want the signature.
- Tap Mobile signature.
- Enter your signature text.
- Tap OK.
To change the signature later, repeat the steps and edit the text in step 6.
If the signature doesn't show up, check the account
Step 4 asks you to choose the Google Account where you want the signature. If you have more than one Google account in the Gmail app, make sure you picked the one you actually send from, then go back to Settings and check its Mobile signature.
What this guide can't confirm yet
We only had Google's Android instructions to work from. That leaves several common questions without a confirmed answer here:
The menu path on Gmail for the web, and any length limit
The steps in the iPhone app
Whether you can add an image or logo, and which formatting is allowed
Whether you can set a different signature for each alias
For any of these, check Google's Gmail Help page on signatures and switch the platform at the top of the page. Many signature-tool vendors publish their own guides too, but they are selling signature products, so treat Google's page as the official reference.
