How to add an email signature in Gmail for Android
On an Android phone, Gmail plays two different roles and it helps to keep them apart. As a reader, it shows the signatures other people send you. As a sender, it adds a signature to what you write on the phone. The app has no HTML editor: its own signature, the “mobile signature”, is plain text only.
This has a consequence almost nobody spells out: if you type a mobile signature, that line of text replaces your logo signature on everything you send from the phone. If you leave it empty, Gmail uses the signature you set in Gmail web, formatting included.
How to check the mobile signature on Android
- 01
First install your HTML signature in Gmail from a computer; that is the one you want to go out.
- 02
Open the Gmail app on Android and tap the ☰ menu at the top left.
- 03
Scroll to Settings and tap the account you use for work.
- 04
Tap “Mobile Signature”. If there is any text, delete all of it and tap OK.
- 05
Send a test email from the phone to another account and open it on a computer to see the full signature.
Check the test in the received email, not on the phone's compose screen: what counts is what reaches the other person. Open it on a computer and on another phone if you can, to see the signature at both sizes.
If you truly need something different on the phone, a short mobile signature with your name and number is honest and works. Just know it carries no formatted links, no colours and no images.
If you decide to use a mobile signature anyway, make it useful: your name, your title and a number with the international dialling code, on one or two lines. Avoid internal abbreviations an outsider wouldn't understand and don't repeat your email address, because the reader already has it in the sender field.
What breaks in Gmail for Android and how to avoid it
When the Android app shows you a received signature, it behaves like Gmail web: it drops flex and grid, ignores the <style> block, does not paint background-image and does not show base64 images. On narrow screens, an outer table wider than 600 pixels forces sideways scrolling, so a fixed width matters more here than on a computer.
The way to avoid it is the same as on the web, with extra care for size: fix the outer table at 600 pixels or less, give every image its width and height, and let the text sit on short lines. Name, title and phone number should be readable without zooming.
| Feature | Gmail for Android |
|---|---|
| <table> layout | Yes |
| display:flex and CSS grid | × No |
| <style> block in the head | × No |
| background-image in CSS | × No |
| Images as data URI (base64) | × No |
| border-radius | Yes |
| letter-spacing | Yes |
| text-transform:uppercase | Yes |
| Web fonts (Google Fonts) | × No |
| max-width and percentage widths | Yes |
| margin on <td> | – Partial |
| <img> without explicit width and height | – Partial |
In total: 5 unsupported, 2 partial and 5 fully supported, out of the 12 features in the matrix. Why each one fails, in the full matrix.
Common mistakes
Pasting HTML into the mobile signature
The field only stores text. If you paste the full signature, you get tags or an unformatted block of text at the end of every email.
Leaving an old mobile signature
A mobile signature you typed years ago, with an old job title or phone number, keeps beating your new signature until you clear the field.
Only checking the personal account
The mobile signature is set per account. If your personal and work accounts share the app, check both.
Frequently asked questions
Can I set a logo signature in the Gmail app for Android?
Not directly: the mobile signature is plain text. What you can do is leave it empty so Gmail uses your HTML web signature, logo included, on what you send from the phone.
Is the mobile signature set per account?
Yes. Each account in the app has its own mobile signature field, under Settings › the account › Mobile Signature.
What happens to base64 signatures on Android?
The app does not show them, same as Gmail web. You can test yours in the free checker.
Are you an AI agent? This is also available as an MCP server at signatureforever.com/mcp