TroubleshootingOctober 8, 2026 · 5 min read

Why Your Gmail Signature Keeps Changing Back (and How to Stop It)

The short answer: almost always, something other than Gmail's own signature setting is putting a signature into your email. The usual suspect is a browser extension or a second signature tool that inserts its own signature a moment after Gmail loads yours. Less often it is the address you are writing from, a different default for replies, a Google Workspace footer your administrator added, or the Gmail phone app, which has its own signature.

The usual causes, most likely first

A signature extension in your browser. Tools such as WiseStamp add a Chrome extension that writes its own saved signature into the compose window after Gmail has inserted yours. That produces exactly the flicker people describe: the new signature appears, then the old one replaces it.
A second tool connected to your Google account. Anything that writes to Gmail's signature setting overwrites the one before it, so whichever ran last wins. Two tools both managing your signature will keep undoing each other.
Signature defaults. Gmail keeps a list of signatures and a separate choice of which one to use for new emails and which for replies and forwards. A reply can use a different one, or none.
The address you are writing from. Each address in your account has its own signature settings. Switching the From address changes the signature.
A footer added by your administrator. In Google Workspace an administrator can append a footer to outgoing messages, which sits below your signature and is not something you can change.
The Gmail phone app. It has its own mobile signature in the app's settings, plain text only, separate from the one you set on a computer.
A Gmail tab that has been open for days. It can keep showing settings from when it loaded. Reload it.

Find which one it is in two minutes

Open a private (Incognito) window and sign in to Gmail. Extensions are off there by default. Start a new email. If the right signature stays, an extension is the cause.
In Gmail's settings (gear icon, See all settings, General, Signature), look at what is saved. If it is the new signature, Gmail has it and something is replacing it as the window opens. If it is the old one, a tool is writing to your account.
Check the Signature defaults just below the signature box: the choice for new emails and the choice for replies and forwards.
In Chrome, open the Extensions page (the puzzle-piece icon, then Manage extensions) and look for anything that mentions signatures.

How to stop it

Pick one tool. Remove the Chrome extension, delete the signature inside the other tool's own account, and take away its access to your Google account at myaccount.google.com/permissions so it cannot write to Gmail again.
Then put the right signature back, and set it for both new emails and replies under Signature defaults.
On your phone, set a plain-text mobile signature in the Gmail app, or leave it empty.

If you use Email Signature Magic

In Settings, under Connections, press Check my Gmail. We read the signature Gmail is holding and compare it with the one we last sent. If they match, Gmail is fine and something in your browser is swapping it. If they differ, it tells you what probably changed it, and Put mine back sends yours again. Each person connects their own Gmail, so a signature tool on one person's browser does not affect anyone else's.

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Frequently asked questions

Why does my new Gmail signature appear and then disappear when I write an email?

Something is replacing it right after Gmail inserts it. The most common cause is a signature extension in the browser, such as WiseStamp, which writes its own saved signature into the compose window. Try a private window: if the new signature stays there, remove the extension.

Does Gmail change signatures by itself?

No. Gmail only uses what is saved in your signature settings. When a signature changes on its own, a tool connected to your account, a browser extension, or an administrator's setting is doing it.

Can two email signature tools work together?

Not reliably. Each one writes its own signature, and the last one to write wins, so they undo each other. Use one tool and remove the other, including its access to your Google account.

Why is my signature different when I reply?

Gmail has a separate setting for replies and forwards. Under Signature defaults, choose the signature for replies as well as new emails.

Why is my Gmail signature missing on my phone?

The Gmail app has its own mobile signature in the app's settings for your account. It is plain text only and separate from the signature you set in Gmail on a computer.