One way we help you do this, is by scanning HTML code when templates are updated, to help identify potential errors and issues, so you can improve templates before they become live. 

Recently we've updated Taxi so that it when you upload new HTML code, will warn you if:

• If you create a replace-(name) attribute that doesn't reference any fields or liquid (for example, a replace-style attribute that just includes regular inline style) - or if you create a replace-(name) attribute with invalid or badly-formed liquid. 
• If you use a liquid filter that doesn't exist or isn't supported.
• If there are any errors or issues in your liquid code (previously some issues wouldn't be shown until previewed in the editor).
• If you specify a rich text style without including rich.selection_text.
• If you create a field that isn't referenced anywhere, or a reference to a field that doesn't exist.
• If the format of a google font link is wrong. The correct link to use is less prominent on google's font site than the wrong one so it is easy to use a link which goes to google fonts, but doesn't render the correct font when an email is sent.

If you are updating an existing template, you may see these warnings for code that has previously passed the scanner with flying colours. You will still be able to update your code into Taxi, but in order to provide the best experience for your template's users, we recommend also updating your HTML to fix these issues. 

We continue to update the template uploading process, and new updates to the code scanner will be added to the what's new section in the platform. You can also see a list of feedback you might see when updating templates. 

We are particularly interested in any false positives, or code issues you have that aren't picked up when uploading HTML, so please do let us know via live chat so that we can make further improvements.