Add your signature to Gmail

⏱ About 60 seconds

In the OnceSig editor, click “Copy signature”.
Open Gmail, click the gear icon (top right), then “See all settings”.
Stay on the “General” tab and scroll down to the “Signature” section.
Click “+ Create new”, give the signature a name, and click “Create”.
Click inside the empty signature box and paste with Ctrl+V (Windows) or Cmd+V (Mac).
Under “Signature defaults”, choose it for “For new emails” and “On reply/forward”.
Scroll to the very bottom of the page and click “Save Changes”.

The #1 mistake: forgetting step 7. The Save Changes button is at the very bottom of a long settings page — if you close the tab without clicking it, Gmail silently discards your signature.

Good to know

10,000-character limit. Gmail caps signatures at 10,000 characters. Every OnceSig template stays safely under it, even fully filled in.
Images must be hosted. Gmail shows images from a public https URL (which is how OnceSig photos work). If your photo doesn't appear, see the Gmail image fix.
The mobile Gmail app is separate. Gmail on iPhone/Android uses its own plain-text “Mobile signature”. Your HTML signature still shows when you send from desktop — recipients on mobile see it perfectly.

Don't have your signature yet?

Build one free in three minutes — every template is pre-tested against Gmail's paste sanitizer.

Open the OnceSig editor