When Mailchimp first introduced its new email builder, it sat alongside the classic editor as something you had to switch on manually from your account settings. That was the experience back when we first wrote about this. A lot has changed since then: the new builder is now the default for almost every Mailchimp account, and the legacy (classic) builder is the one being wound down feature by feature rather than getting new updates.
If you’re not sure which builder you’re currently using, or you’ve been putting off the switch because the legacy builder “just works,” here’s where things stand in 2026: what the new builder can do, what it still can’t do, and how to move over without losing anything important.
New builder vs. legacy builder: the short version
Both builders still exist inside Mailchimp, and both let you drag and drop content blocks into a campaign. The real difference comes down to where Mailchimp is putting its development time.
The new builder gets the new stuff: an AI-powered content generator that can draft subject lines and email copy, a built-in Content Studio for managing your brand’s images and assets, dynamic content blocks that show different content to different segments of your audience, and an updated interface with proper undo and redo.
The legacy builder is mostly frozen in place. It still works, and it’s still the only place where you can paste in a fully custom-coded HTML template or set up an RSS-driven campaign (an email that automatically pulls in your latest blog posts). If neither of those applies to you, there’s very little reason left to stick with it.
How to check which builder you’re using right now
If you opened a Mailchimp account in the last couple of years, you’re almost certainly already on the new builder by default and can skip this section. If your account has been around longer, here’s how to check and switch.
Go to your Account page.
Hover over Settings and select Details.
Scroll down to the email builder section, and select the box on the right: New Builder.
Now, when you go to create your next email campaign, you’ll see the new editor.
A tour of the new builder
This editor is built around drag-and-drop content blocks. Hover over any block in the side panel, then click and drag it into your campaign layout to add it.
The text block is where most of your editing time goes. Add your copy, then highlight any portion of it to make inline style changes, bold, italics, links, colors, without leaving the block.
You’ll also have access to a wide range of web fonts, which Mailchimp adds to and updates on a regular basis. This is worth a look even if you’re happy with your current template, since a font refresh is one of the quickest ways to make an email feel less dated.
The image block works much like it always has: add an image, edit its size and alignment, and link it to a page on your site.
Beyond text and images, the same drag-and-drop panel includes blocks for buttons, dividers, social follow icons, and video, plus product and abandoned cart blocks if you have a connected store. If you’ve used the legacy builder before, the block types will feel familiar. It’s the editing experience around them that’s changed.
What’s been added since this builder first launched
The original version of the new builder was a fairly stripped-back drag-and-drop tool. Since then, Mailchimp has layered on a few features that are genuinely worth using:
- AI Email Content Generator. Describe what you want to say, and Mailchimp drafts subject lines and body copy you can edit from there. We’ve covered how to get useful results from it in this guide to Mailchimp’s Email Content Generator.
- Content Studio integration. Your brand’s logos, product photos, and other assets are easier to pull straight into a campaign without digging through old uploads.
- Apps and Survey blocks. Pull in content from connected third-party platforms, or drop a feedback survey directly into an email.
- Dynamic content blocks. Show different content to different segments of your audience within the same campaign, instead of building separate emails for each group.
- Undo and redo. A small thing, but if you’ve ever lost ten minutes of layout work to a stray click, you’ll appreciate it.
What you’d lose by switching
For most accounts, switching to the new builder is a straightforward upgrade with no real downside. Two situations are worth flagging first.
Custom-coded templates. If you or a developer built a template using custom HTML, that template needs the legacy builder to be edited. The new builder will pull a legacy-built email into its layout if you open it there, but you won’t be able to get back into the original code from the new builder.
RSS campaigns. If you run an RSS-driven campaign, one that sends automatically whenever you publish a new blog post, that’s still a legacy-only feature.
If either applies to you, you don’t have to pick one builder for your whole account. Keep your default set to whichever you use most, and switch builders on a template-by-template basis for the ones that need custom code or RSS.
Should you make the switch?
If you’re not relying on custom code or RSS campaigns, yes. The legacy builder isn’t going to gain any new functionality, and the gap between the two editors will only widen. Switching now means your team gets familiar with the AI drafting tools, dynamic content, and newer block types before you need them for a specific campaign.
Quick FAQ
Can I switch back to the legacy builder? Yes. The same Account > Settings > Details screen lets you change your default builder at any time.
Will switching affect my existing templates and campaigns? Your sent campaigns are untouched. Changing your account’s default builder doesn’t alter anything in your template library. If you do open an older, legacy-built template inside the new builder, Mailchimp will pull that design into the new builder’s layout, which is usually fine but worth checking over before you send.
Does the new builder support RSS campaigns yet? Not at the time of writing. RSS-to-email is still a legacy builder feature.
If you’re not sure which builder makes sense for your account, or you’d like a second pair of eyes on your Mailchimp setup before you start moving templates around, get in touch with the Chimp Essentials team.
