// HOW-TO GUIDE
How to add a signature in Gmail
Gmail's signature setting is buried three screens deep, and it has two rules that catch people out: images have to be hosted online, and the whole signature has to fit under 10,000 characters. This guide walks through the desktop steps, both of those rules, and what the Gmail app on your phone does with the signature.
Need a signature first? Make one free in two minutes. The Web Blend generator builds a signature with your logo, licence number and phone, with the images hosted so Gmail shows them, and sized to stay well inside Gmail's character limit.
Make a free signature// GMAIL ON DESKTOP
Add a signature in Gmail on a computer
Do this in a desktop browser. The signature you save here is what goes out on every email you send from a computer, and it is the source the iPhone Gmail app can pull from.
- Open the full settings. Click the gear icon at the top right of Gmail, then See all settings.
- Find the Signature section. Stay on the General tab and scroll down to Signature.
- Click Create new, give the signature a name, and click Create.
- Paste your signature into the box with Ctrl+V on Windows or Cmd+V on a Mac. If you built it in the generator, click Copy signature there first. The logo appears straight away because it is a hosted image.
- Set the defaults. Under Signature defaults, pick the new signature for new emails and for replies and forwards.
- Save. Scroll to the bottom of the page and click Save Changes. Gmail does not save on its own.
- Check it. Click Compose and confirm the signature and logo appear in the new message.
// IMAGES
Why your logo has to be hosted online
Gmail does not store signature images. It only displays an image that lives at a public web address, and it needs that address to start with https. If you paste a logo from a file on your computer, or drag one in from a folder, Gmail either shows a broken image box or silently drops it.
Gmail's own image button offers three options: Drive, Upload and Web Address. The first two are unreliable, and Google's published fix for a failed upload is to try again in an incognito window. The Web Address option is the one that works every time. A signature built in the Web Blend generator already references hosted images, so you paste once and skip the image button entirely.
// THE 10,000 CHARACTER LIMIT
Fix the "signature is too long" error
Gmail caps each signature at 10,000 characters, and it counts the hidden HTML that carries the layout, not just the words you can see. A simple signature with a logo uses a fraction of that. Hit the error and one of three things has happened.
- You pasted more than the signature. Copying from a web page or a Word document often brings surrounding content with it. Clear the box, click Copy signature on the generator, and paste once.
- An old signature is still in the box. Pasting on top of an existing signature doubles the size. Select all inside the box, delete, then paste.
- The signature was built in a heavy editor. Word, Canva and some signature tools export thousands of characters of styling for a few lines of text. Rebuild it in a tool that outputs lean HTML. The generator keeps its output well under the limit.
The free generator shows a live count against the 10,000 character limit as you build, so you know it will fit before you paste.
// GMAIL ON YOUR PHONE
What the Gmail app does with your signature
The Gmail app does not share the desktop signature setting, and the two platforms behave differently.
- Android: plain text only. The Android Gmail app has its own Mobile Signature under Settings, then your account. It is plain text, so your logo and layout do not carry across. Type a short version there: name, business, phone and website on separate lines.
- iPhone: can use the web signature. In the Gmail app, go to Settings, your account, then Signature settings. Leave Mobile Signature switched off and the app uses the full signature you saved on desktop, logo included. Switch it on and you get a plain-text mobile version instead.
- Emails from a computer always use the web signature. Whatever you set on your phone, the full signature goes out on everything you send from Gmail in a browser.
- Using Apple Mail or the Outlook app with your Gmail address? Those apps keep their own signatures. The generator's install tab covers each one.
If you built your signature in the free generator, switch the output to Phone. It gives you a plain-text version with the same details, ready to paste into the Android app or the Mobile Signature box on iPhone.
// TROUBLESHOOTING
When the signature still will not behave
The signature is not on new emails
You created it but did not set it as a default. Go back to Settings, then General, then Signature defaults, and pick it for new emails. Then scroll down and click Save Changes.
The signature is missing on replies
Set the second Signature defaults dropdown, the one for replies and forwards. Gmail also hides the signature under the three-dot button below the quoted text in a reply, so click that to confirm it is there.
The logo is a broken image box
The image is not hosted, or its address starts with http rather than https. Re-paste a signature with hosted images. Check the hosted file is still online too: deleting the logo from your website deletes it from every signature that points at it.
The fonts look different from the preview
Gmail only renders fonts the recipient has installed, so a signature built on a decorative font falls back to something plain. Stick to web-safe fonts like Arial or Georgia, which is what the generator uses.
You use Outlook as well
Outlook stores signatures in a different place, with its own paste problems. See how to add a signature in Outlook.
// QUESTIONS
Gmail signature questions
Still stuck? Build the signature in the free generator and use the install tab there, which has the same steps for Gmail, Outlook, Apple Mail and your phone in one place.
Open the generatorWhy does my logo not show up in the Gmail signature?
Gmail only displays signature images that are hosted at a web address. If you pasted an image from your computer, or the address starts with http rather than https, Gmail drops it. Use a signature whose logo is hosted online, which is how the Web Blend generator builds them, and paste it again.
What does "Your signature is too long" mean?
Gmail caps each signature at 10,000 characters, counting the hidden HTML as well as the text you can see. You usually hit it by pasting extra page content or an old signature alongside the new one. Clear the box, copy the signature again from its source and paste once.
Can I have more than one signature in Gmail?
Yes. Click Create new as many times as you need, give each one a name, and pick which one to use from the pen icon at the bottom of any message you are writing. Signature defaults let you set one for new emails and a different one for replies.
Why is my signature missing when I reply?
Gmail has separate defaults for new emails and for replies and forwards. Go back to Settings, then General, then Signature defaults, and pick your signature in both dropdowns. Gmail also tucks the signature below the quoted text in replies, behind the three-dot button, so it is there even when it looks missing.
Does the Gmail app on my phone use the same signature?
Not on Android. The Android Gmail app has its own plain-text Mobile Signature and does not carry your logo or layout. The iPhone Gmail app can use the web signature if you leave Mobile Signature switched off in the account settings. Emails sent from a computer always use the full web signature.
// FREE TOOL
Build a signature Gmail will actually show
Hosted logo, web-safe fonts, well under the character limit. Name, licence number, phone and website laid out properly. Free, no sign-up, no watermark.
Make a free signature