Email tools that keep your own HTML (2026)
The best email builder for custom HTML templates depends on what you want to happen to the HTML. Some tools keep it as written and add a form on top, which is what Modular Mail does with one attribute, data-mm, before exporting to Salesforce Marketing Cloud, Braze, Marketo or any ESP. Some import it and rebuild it in their own blocks, as Stripo and RGE Studio (formerly Beefree) do. Some, such as MJML and Parcel, are where the HTML gets written in the first place. Here are fourteen, grouped that way, with what each does well.
Updated 3 November 2026. We make Modular Mail; it's listed in its group, not first.
The short answer, by who's doing the work
A developer writes every email
Nobody writes HTML
Enterprise marketing ops
A developer's templates, a marketer's sends
How this list was put together
One question sorts every tool here: what does it do to the HTML you give it?
Each tool was checked on its own website on 3 November 2026, and the research notes link to the page each claim came from. Where a site doesn't say something, the entry says to check rather than guessing. There are no affiliate links. We make Modular Mail, which is the only tool in its group; it's described the same way as the rest, and the fit lines say who it isn't for.
The things compared, for every tool:
- What happens to your HTML: kept as written, rebuilt in the tool's blocks, or written in the tool's own language
- Who does the day-to-day editing, a developer or a marketer
- How the finished email reaches the ESP: HTML export, a direct connector, or both
- Whether review and approval happen in the tool
- Whether the price is published
Unlayer, GrapesJS, Blocks, Tabular, Litmus Builder and MailEditor come up in the same searches. They aren't covered yet; this page is reviewed quarterly and they're on the list.
Fourteen email tools, compared by what they do to your HTML
| Tool | Kind | What happens to your HTML | Who edits day to day | To the ESP | Review in the tool | Pricing |
|---|---|---|---|---|---|---|
| MJML | Open-source framework | You write <mj-*> markup; it compiles to table-based HTML | Developer | HTML, any ESP | No | Free |
| React Email | Open-source library | You write React components; they render to HTML | Developer | HTML, any ESP | No | Free |
| Maizzle | Framework | You write HTML with Tailwind classes; it compiles to pure HTML | Developer | HTML, any ESP | No | Free |
| Parcel | Coding platform | Kept as you write it; optional transformers inline CSS and strip unused code | Developer, with a visual editor for others | ZIP of HTML, AMP and text | Comments, share links, approvals | Published |
| Stripo | Visual builder with code editor | Imported files open in the code editor; layout changes stay in code, or Stripo rebuilds it as a master template | Marketer in the builder, developer in code | HTML export, or integrations with 90+ ESPs | Roles and co-editing | Published |
| RGE Studio (formerly Beefree) | Visual builder | Imported files auto-convert into the builder's rows and blocks | Marketer | HTML export and integrations | Approvals; a Manager role locks rows | Published, free plan |
| Postcards | Visual builder | Imported files become editable in the builder | Marketer | HTML or ZIP, one-click export to named platforms | Comments, editor and viewer roles | Published |
| Chamaileon | Collaborative builder | Imported code is converted into a reusable template | Marketer | Integrations and export | Approve or reject in the editor; lockable blocks | Published |
| Topol | Visual builder, embeddable | Built on MJML; import not stated on its site | Marketer | HTML; check connectors | Not stated | Published |
| Knak | Enterprise production platform | Imported HTML is cleaned up and built in Knak | Marketer, within guardrails | One-click sync to Marketo, Eloqua, Marketing Cloud, Pardot; API | Comments and approvals | On request |
| Stensul | Enterprise production platform | Modules are built in Stensul | Marketer, from approved modules | Deploys to Marketing Cloud, Journey Optimizer, Marketo, Eloqua, Responsys | Approvals, audit trail | On request |
| Dyspatch | Template management platform | Blocks are written in DML, Dyspatch's markup | Marketer, from blocks | Sync to Salesforce, HubSpot, Marketo; code export; API | Annotated comments, approval workflows | Published |
| Taxi for Email | Email design system | Your HTML with Taxi Syntax tags added | Marketer, from modules | HTML download or direct connectors | Permissions | On request |
| Modular Mail | CMS for email | Your HTML, as written, with data-mm on the editable elements | Marketer, in fields | Copy or download HTML, any ESP | Comments, review requests, approval on record | Published |
| ESP-native editors | Built into the platform | Varies: Marketing Cloud and Klaviyo add regions to your HTML, Marketo needs its syntax, Braze and Mailchimp's newer builders rebuild it | Marketer in the regions; developer elsewhere | Already there | The ESP's own | With the ESP |
Details are from each tool's public website and documentation, checked 3 November 2026. "Published" means a price list is on the site. Modular Mail isn't affiliated with any other tool here.
Sources: Tool websites and documentation, MJML, React Email, Maizzle, Parcel, Stripo, Stripo: How to import your own design, RGE Studio, RGE Studio: HTML emails to editable designs, Beefree content locking, Postcards, Chamaileon, Topol, Knak, Stensul, Dyspatch, Taxi for Email.
Frameworks and editors for teams that write the HTML
Your HTML stays yours because you wrote it here. The trade is that every send goes through someone who can.
MJML
Best for: developers who want responsive email without hand-building nested tables.
MJML is an open-source markup language: you write <mj-section> and<mj-column> and it compiles to the table-based, inline-styled HTML that email clients expect, with Outlook handled. It was created by Mailjet developers in 2015 and has a large component ecosystem. There's no marketer-facing editor; the output is a file you hand to whatever sends it.
Check before choosing: how the team will edit copy once the template is compiled. MJML answers the build problem, not the editing one.
React Email
Best for: product teams already in React who want transactional email in the same codebase.
An open-source library of unstyled components, written in React and TypeScript, that render to email HTML. The repository sits under Resend, and it fits a workflow where emails are code reviewed like any other component. Marketing teams without an engineer in the loop won't get far with it on its own.
Check before choosing: whether your ESP's merge tags fit comfortably inside components, and who edits the words.
Maizzle
Best for: developers who think in Tailwind.
Maizzle is a framework for building HTML emails with Tailwind CSS utilities, compiled to plain HTML "so you can use any email service provider". It runs from the command line or as a library and ships a live-preview dev UI. As with MJML, the editing experience for non-developers is whatever you build around it.
Check before choosing: the build step's place in your deploy pipeline, and whether a marketer will ever need to touch a template.
Parcel
Best for: email developers who want a browser-based editor with email-specific tooling, plus a place for the team to review.
Parcel calls itself "The Email Coding Platform": a code editor that knows email, with components, formatters and optional transformers that inline CSS and remove unused code at export. There's a visual editor for people who don't write code, share links and approvals, and test sends to up to nine teammates. Exports are a ZIP of the processed HTML, AMP and text.
Check before choosing: how far the visual editor goes for a marketer working alone, and whether the transformers change anything you'd rather keep as written.
Builders that import your HTML and rebuild it
These are the tools most roundups put first, and for good reason: anyone can use them. The thing to know is what import means in each.
Stripo
Best for: teams that want a drag-and-drop editor and a code editor side by side, and a long list of ESP connections.
Stripo's builder and its HTML and CSS editor work together without switching, with more than 300 modules, synchronised modules for bulk edits, custom roles and co-editing. It exports HTML and lists integrations with more than 90 ESPs. An imported HTML file opens in the code editor; Stripo's help centre says layout and structure changes then have to be made in the code, and offers a paid Template Order service that rebuilds your HTML as a native master template.
Check before choosing: whether you want your templates rebuilt as Stripo templates. If yes, it's a strong builder. If your developer maintains the HTML, the two copies will drift.
RGE Studio (formerly Beefree)
Best for: marketers designing from blocks who want a free way in and locking for the parts that shouldn't move.
The Beefree builder became RGE Studio in 2026; the embeddable Beefree SDK is a separate product. Its HTML importer takes a file and, in its own words, auto-converts it into the drag-and-drop builder. A Manager role can lock rows, there's a free plan, and the integrations list is long. It's a good fit for a team that will live in the builder.
Check before choosing: what the converter does with your Outlook fixes and custom layouts. Import a real template before you commit.
Postcards
Best for: small teams and freelancers who want a polished block editor and a clean HTML download.
Designmodo's Postcards builds from drag-and-drop blocks and more than a hundred ready-made modules, with real-time co-editing, comments and viewer seats. It imports existing HTML on paid plans (free accounts get five imports), downloads HTML or a ZIP, and offers one-click export to platforms it names including Mailchimp, HubSpot, Klaviyo, Brevo and SendGrid.
Check before choosing: how an imported template behaves in the editor, and whether your ESP is one of the named exports or a plain HTML paste.
Chamaileon
Best for: teams whose main problem is approval, with a few people editing at once.
Chamaileon is a collaborative builder: pre-coded blocks, real-time editing, approve or reject inside the editor, roles per folder, and lockable blocks. Imported HTML is "automatically converted into a reusable email template". Integrations listed include Mailchimp, Iterable, Marketo, Braze and HubSpot, and there's an SDK for products that want to embed it.
Check before choosing: the conversion. As with the others in this group, the result is Chamaileon's template, which suits a team that will build there from now on.
Topol
Best for: software products that want to embed an editor, and small teams who want a plain builder on MJML.
Topol is a drag-and-drop editor built on MJML, offered as an SDK and as a standalone Pro editor, hosted in the EU, with more than 400 templates and a 14-day trial. Its homepage is clear about what it handles for you (Outlook, the quirky inboxes) and quiet about import.
Check before choosing: whether existing HTML can be brought in, and which ESP connectors exist. Neither is stated on the homepage.
Enterprise platforms with modules, guardrails and direct sync
Built for marketing ops teams at scale, priced and sold that way. If you send from Marketo, Eloqua or Marketing Cloud and have a procurement process, these are the names you'll hear.
Knak
Best for: enterprise marketing ops teams on Marketo, Eloqua, Marketing Cloud or Pardot who want one-click sync.
Knak describes itself as a production layer between brief and send: no-code email and landing page builders, brand guardrails as a feature of the system, HTML import with AI cleanup, more than 40 integrations and an open API, with comments, reviews and approvals in one place. Pricing is by demo.
Check before choosing: budget and team size. Knak is built for enterprise and priced for it; a ten-person team pasting HTML into one ESP will find it more platform than they need. How Modular Mail compares with Knak.
Stensul
Best for: large, regulated organisations that need legal and brand checks built into creation.
Stensul positions itself as an AI governance harness for enterprise email: approved modules, brand, legal and accessibility checks during creation, approvals that stand up to audit, and deployment to Marketing Cloud, Adobe Journey Optimizer, Marketo, Eloqua and Responsys. It names financial services, healthcare and pharma as home ground. Pricing is on request.
Check before choosing: whether your ESP is on its deploy list, and whether you need the governance layer or a simpler locked template. How Modular Mail compares with Stensul.
Dyspatch
Best for: teams sending transactional and marketing email at volume who want modules a developer builds and marketers assemble.
Dyspatch is template management with a no-code builder on reusable modules written in DML, its own markup language. It has annotated comments and approval workflows, sync to Salesforce, HubSpot and Marketo, code export and API access on every plan, localisation on Teams+ and published pricing.
Check before choosing: that your developer is happy to write blocks in DML rather than keep plain HTML.
Taxi for Email
Best for: brand and agency teams that want an email design system with direct ESP connectors.
Taxi builds a modular Email Design System from your HTML marked up with Taxi Syntax. Marketers assemble emails from the modules, permissions are set per team member, and the finished email is downloaded as HTML or pushed through a direct connector. It syncs with Litmus for previews.
Check before choosing: the syntax, which someone has to learn and maintain, and the price, which you'll only get on a call.
A CMS for email: your HTML, marketers' fields
One tool in this group, and it's ours.
Modular Mail
Best for: teams and agencies that already have custom HTML templates, send often, and want marketers to build campaigns without a developer or a rebuild.
Modular Mail stores your template as the HTML your developer wrote. The parts that change carry one attribute, data-mm, and become fields with rules: a character limit, a required flag, an approved list of colours. Marketers pick modules, fill in the fields, choose images from a media library the workspace shares (uploads are hosted, so the exported HTML points at them), drag modules into order, send a test and get approval in the same place, then copy or download the HTML for Salesforce Marketing Cloud, Braze, Marketo, Klaviyo or any ESP that accepts it. The HTML is never rewritten; values are spliced into the original at export. Template setup is part of onboarding.
It isn't for teams designing a fresh layout every week, which is a builder's job, and it doesn't send campaigns, connect to an ESP by API or keep a version history.
Check before choosing: that you have, or will commission, coded templates. There's no block library to start from.
The editor that came with your ESP
Sometimes the right answer is the one you already pay for. What each platform does with a custom HTML template:
Salesforce Marketing Cloud
A Paste HTML template is edited as code unless a developer adds content areas (data-type="slot") that marketers fill with blocks; areas can be locked. Good when every send stays in Marketing Cloud and someone will maintain the slots.
Marketers editing custom HTML in Marketing Cloud
Braze
The HTML editor keeps your code and opens it to people who read HTML; the drag-and-drop editor is for everyone but a custom template has to be re-created in it first. Content Blocks share pieces between messages through Liquid.
Making Braze templates editable
Marketo
The classic editor opens regions marked with Marketo's syntax (mktoText,mktoModule). The newer Email Designer imports HTML into Compatibility mode, where text, links and assets change, and converts it to its own components for anything more.
Marketo's template syntax, explained
Mailchimp
Custom-coded templates take mc:edit areas in the classic template builder; Mailchimp calls it an advanced feature. A fit for one-ESP teams with a developer who's comfortable with the template language.
Klaviyo
A hybrid template keeps your HTML intact and adds editable regions by pasting adata-klaviyo-region snippet, one per region, which marketers fill with blocks. Klaviyo suggests custom HTML for technically savvy marketers or teams with developer access.
Sources: Platform documentation, Marketing Cloud: Add Content to a Paste HTML Template, Braze: Create an email template, Marketo Email Template Syntax, Marketo Email Designer template import, Mailchimp Template Language, Klaviyo: How to create a hybrid email template.
64%
of email teams add a tool beside their ESP, and 76% do at large companies. The same survey rated ESPs six out of ten on average, which is roughly why this page exists.Really Good Emails survey, nearly 1,700 email professionals, June 2025
What's the best email builder for custom HTML templates?
It depends on what you want to happen to the HTML. If a developer will write and maintain it, MJML, Maizzle or Parcel. If you want to rebuild it in a visual editor and work there from now on, Stripo, RGE Studio or Postcards. If you want to keep it exactly as coded and let marketers fill in fields, a CMS for email such as Modular Mail. What is an email CMS?
Which WYSIWYG email editor exports clean HTML?
Stripo, RGE Studio, Postcards and Chamaileon all export HTML you can paste into an ESP, and each has a connector list. Modular Mail exports your own HTML with the fields filled in, so "clean" means the code your developer wrote. Parcel's transformers can inline CSS and strip unused code on the way out.
What are the alternatives to Stripo and Beefree if we want to keep our own HTML?
Parcel and the code frameworks (MJML, Maizzle, React Email) keep the HTML because you write it there. Taxi for Email keeps it with its syntax tags added. Modular Mail keeps it as written and adds data-mm to the parts that change. Beefree itself is now RGE Studio, and both it and Stripo rebuild imported files in their blocks. Modular Mail as a Stripo alternative
Does importing HTML into Stripo or RGE Studio change the code?
Both rebuild the file in their editor. Stripo's help centre says that after import, layout and structure changes still have to be made in the HTML, and offers a paid service to rebuild the template natively. RGE Studio describes its importer as auto-converting the file into its drag-and-drop builder. That's fine if the builder becomes the home of the design. Email CMS vs email builders
Can our ESP's own editor edit a custom HTML template?
Partly. Marketing Cloud and Klaviyo let a developer add editable regions to your HTML; Marketo needs its own syntax; Mailchimp has mc:edit in the classic builder; Braze edits custom HTML as code or has it rebuilt in the drag-and-drop editor. Each works only inside that ESP. Four ways to make a coded template editable
Is MJML an email builder?
No. It's a markup language that compiles to email HTML. Several builders, Topol among them, are built on it, and Parcel supports it, but MJML on its own has no marketer-facing editor.
Can Canva make HTML emails?
Yes. Canva Email exports HTML and can push it to Mailchimp, Klaviyo, Braze and a few others. The export is a snapshot rather than a template, so each change goes back through Canva. Can Canva create HTML emails?
Why is Modular Mail on its own list?
Because it's the only tool here that keeps your HTML as written and gives marketers fields, and because leaving it out would be odd on our own site. It's described the same way as the others, in its own group, with the teams it doesn't suit named.
How often is this page updated?
Quarterly, and whenever a tool here changes its name or its import behaviour. The date at the top is the last check.
Want to see your own template with fields on it?
Send us a recent email and we'll mark it up with data-mm before the call. If a builder would suit your team better, we'll say so.