What Is HTML Inserter for Gmail?
HTML Inserter for Gmail is a Chrome extension that adds a side panel to Gmail. It lets you write, preview, and insert HTML emails, manage a template library, and edit your Gmail signature — all without leaving Gmail.
Core Features
- Template library with categories & filters
- HTML editor with preview window
- One-click insert into Gmail compose
- Signature editor for Gmail settings
- JSON import & export for templates
- Quick-access template bar
Feature Guide
📁 Templates Library Templates
This is the default tab. It shows all your saved HTML templates organized by category.
| Feature | Description |
|---|
| Filter by type | Click All, Email, or Signature to filter templates by their tag. |
| Search | Use the search box to find templates by name or description. |
| Category groups | Templates are grouped into folders. Click a folder header to collapse or expand it. |
| Quick insert | Hover over a template card and click the insert icon to immediately open a compose window with that template. |
| Edit a template | Click a template card to load its HTML into the Editor tab, where you can modify and save it. |
| Delete a template | Click the delete icon on a template card. The extension will ask for confirmation before removing it. |
| Import templates | Click the Import button in the top bar. Choose a .json or .html file to import. For JSON files, existing templates with the same name in the same category will be skipped. |
| Create a new template | Click New. Enter a category and a name. You'll be taken to the Editor tab where you can paste your HTML and save it. |
✏️ Editor Editor
Write or paste HTML code and preview it before inserting into an email.
| Feature | Description |
|---|
| HTML textarea | A monospace text area where you can paste or type HTML code. It supports any valid HTML that Gmail supports. |
| Paste from clipboard | Click 📋 Paste to read HTML from your clipboard. You can also use Ctrl+V (Cmd+V on Mac). |
| Clear editor | Click 🗑 Clear to remove all content from the editor. |
| Preview | Click 👁 Preview to open a popup window showing how your HTML will look in a browser. |
| Insert into email | Click Insert into email to open a new compose window in Gmail with your HTML inserted into the body. |
| Save as template | Click 💾 Save as Template to store the current HTML into the template library. You'll be prompted for a name. |
| Quick templates | The bottom section shows up to 5 recently-used templates. Click one to load its HTML into the editor immediately. |
📝 Signature Editor Signature
Edit your Gmail signature with custom HTML directly from the side panel.
| Feature | Description |
|---|
| Automatic detection | When you're on the Gmail Settings → General → Signature page, the extension automatically detects the signature editor and reads its content. |
| Load current signature | The extension checks for the signature editor every 5 seconds. When it's found, the content is shown in the editor. |
| Edit signature HTML | Modify the HTML content in the textarea. You can use the Paste and Clear buttons just like the Editor tab. |
| Preview signature | Click 👁 Preview to see how your signature will look. |
| Load into Gmail | Click Load into Signature to write your edited HTML back into the Gmail signature editor. Important: After writing, you must click Gmail's Save Changes button at the bottom of the settings page. |
| Save signature as template | Click 💾 Save as Template to store your signature HTML in the template library for later use. |
The signature feature only works on the Gmail settings page: mail.google.com → Settings (gear icon) → See all settings → General → Signature. It does not work on the inbox or compose view.
👁 Preview Window
When you click the Preview button in either the Editor or Signature tab, a popup window opens displaying the rendered HTML. The preview uses an isolated environment so your HTML displays exactly as it would in an email. Click Refresh to reload the preview, or Close to close it.
⚡ Quick Templates
In the Editor tab, the Quick Templates section at the bottom shows up to 5 templates for fast access. Click any quick template to load its HTML into the editor. Click View All → to switch to the Templates tab.
Frequently Asked Questions
The side panel says "Current page is not Gmail".
The extension only works on mail.google.com. Make sure you have a Gmail tab open and active, then click the extension icon again. If the issue persists, try refreshing the Gmail tab.
The extension is not responding. Buttons don't do anything.
This usually means the extension's
content script failed to connect to the page. Try these steps:
- Refresh the Gmail page (F5 or Ctrl+R).
- If that doesn't help, go to Chrome's extension management page (Chrome menu → Extensions → Manage Extensions), find "HTML Inserter for Gmail", and click the refresh icon on the extension card.
- As a last resort, remove and re-install the extension.
If none of these work, please
contact the developer with a description of what you were doing and any error messages you saw.
The Insert button opens a compose window but the HTML is not inserted.
Gmail may take a moment to fully load the compose window. The extension waits up to 15 seconds for it. If the insert still fails:
- Make sure you don't have any browser extensions that block or modify Gmail's compose window.
- Try closing any existing compose windows and clicking Insert again.
- If the issue only happens with certain emails, the HTML may contain unsupported tags. Try a simpler version first.
"Signature editor not found".
The signature editor detection only works on the Gmail
Settings → General → Signature page. Follow these steps:
- Click the gear icon in Gmail's top-right corner.
- Click See all settings.
- Go to the General tab.
- Scroll down to the Signature section.
- If you don't have any signatures yet, create one first (Gmail requires at least one signature to show the editor).
- Click on the signature editor area so it's focused, then wait a moment for the extension to detect it.
If it still doesn't detect it, make sure you're not on the
Vacation responder section — the extension specifically looks for the signature editor.
I clicked "Load into Signature" but nothing happened in Gmail.
The extension writes the HTML into Gmail's signature editor, but Gmail does not save automatically. After clicking "Load into Signature", you must scroll down to the bottom of the settings page and click Gmail's Save Changes button. Your signature will not be saved if you leave the page without clicking Save Changes.
Where are my templates stored? Will I lose them if I clear my browser data?
All templates are stored in Chrome's
sync storage (if you're signed into Chrome) or
local storage. This means:
- Templates persist across browser restarts.
- They are not affected by clearing your browsing history or cookies.
- If you clear site data or extension data in Chrome settings, the templates will be deleted.
We recommend using the
Export feature (coming soon) to back up your templates regularly. For now, you can use
Import/Export via JSON by clicking the Import button.
The extension stopped working after a Chrome update.
Chrome updates can sometimes affect extensions. Try these steps:
- Go to Chrome's extension management page (Chrome menu → Extensions → Manage Extensions).
- Find "HTML Inserter for Gmail" and click the refresh icon on the card (this reloads the extension).
- If that doesn't help, disable and re-enable the extension.
- As a last resort, remove the extension and install it again from the Chrome Web Store.
If the problem persists, reach out to the developer with your Chrome version and a description of the issue.
Why is there a charge for this extension?
We want to be upfront with you. Behind this extension are real costs — keeping the service reliable, fixing bugs, adding new features, and providing support when you need it. The subscription helps us cover these costs so we can continue improving your experience. We offer a free trial so you can make sure it's right for you before committing.
How do I contact support or report a bug?
You can reach us at either of these email addresses:
When reporting an issue, please include:
- The URL of the page you were on.
- What you were doing when the problem occurred.
- Any error messages you saw in the side panel.
- Your Chrome version (go to Chrome menu → Help → About Google Chrome).
The more detail you provide, the faster we can help you!
