Build your own email editor, or embed Topol Plugin. A finished white-label email editor with previews, test send and version history, maintained by Topol, from $70 a month.
- Building email editors since 2017
- Built and hosted in the EU
- 14-day trial, no card
Building your own email editor is the wrong call unless the editor is your product or you need output other than email HTML, because a team can ship version one in about a quarter and the rendering fixes after it keep coming for as long as your customers send email. Topol's editor started as an in-house build, and its team spent about 6 months on version one and the next 2 years on rendering work for clients from Outlook 2000 to Gmail on Android. Topol Plugin is the finished white-label editor that came out of that work, with Business at $300 a month for 500 prepaid users and $0.70 per extra user.
$68,000 Salary for two developers, one quarter
2 years Of rendering work after version one
90+ Email clients rendered correctly
$300 per month, Business, 500 users
Trusted.
- If two developers spend a quarter on version one of an email editor, salary alone is about $68,000 at the US Bureau of Labor Statistics software developer median of $135,980 a year.
- Every platform that embeds Topol Plugin reports the breaks its users find, and Topol's changelog lists 76 fixes in 19 months, each shipped through Topol's loader to the platforms that embed it.
- Topol Plugin emails compile through open-source MJML and render correctly in 90+ email clients, old Outlook included, and Topol tests the output itself.
- Lettr by Topol sends what Topol Plugin users build.
Facts and prices checked on 23 October 2026. Sources
Topol Plugin is a finished email editor, and every fix reaches the SaaS platforms that embed it.
Topol Plugin Business at $300 a month is a finished white-label editor, so your developers stay on the product your customers pay for.
One fix, every platform
A break reported on any platform that embeds Topol Plugin gets fixed for all of them, through Topol's loader URL.
Embedded in about a week
Customerscore.io, a retention platform, embedded Topol Plugin in about a week. Your save flows and user roles set how long yours takes.
Templates stay yours
Templates save as JSON to your own storage, and you export HTML at any time. Topol never stores them.
Previews and test send built in
Desktop, mobile and dark-mode previews come built in, with merge tags filled in. Test emails go out through your own sender.
Uploads and sandboxing
The File Manager resizes uploads and checks each file's type by its leading bytes. The editor runs in a sandboxed iframe.
Comments, roles and languages
The $300 Business plan adds comments, roles, synced sections and multilingual templates. The editor interface ships in 21 languages.
Viktoria Camp, Co-Founder and CEO of Affinect, a hospitality marketing platform, says, "From the beginning, we knew we did not want to build our own email design system." Message34, a messaging platform, has run Topol Plugin for over five years with low maintenance.
You can build version one of an email editor in about a quarter, and its systems keep needing work after launch.
The drag-and-drop canvas is the part your developers prototype first, and each system behind it keeps needing work once your customers send email.
Outlook renders with Word
Classic Outlook renders email with Word's engine, so every block needs nested tables. One missed workaround breaks your customer's campaign.
Each client has its own dark mode
Gmail, Outlook, Apple Mail, Yahoo and others apply their own dark-mode rules. Litmus, a testing company, puts dark-mode readers above 25%.
Templates are user HTML
Templates are HTML your users supply. A script saved in one template runs for whoever opens it next, including your support team.
Every saved template migrates
Each change to your template format means migrating every template your customers ever saved, in every account.
Every upload needs checks
Every image your customers upload needs storage, bandwidth and a file check. Your team owns those checks while the editor runs.
Support tickets follow
Users of Message34's built-in editor turned to its support team regularly. Its design-related requests fell about 30% after switching to Topol.
Before Topol, Customerscore.io, a customer retention platform, tried other editors, and Topol's case study says their emails "often looked different in inboxes than they did in the editor". Its customers tested and adjusted templates by hand for each device and email provider.
If two developers build version one of an email editor in a quarter, their salary is about $68,000.
After launch, every month a developer spends on the editor costs $11,332 in salary at the same median.
Topol Plugin Business
$300 per month
- 500 prepaid users, $0.70 per extra user
- Every editor feature: custom blocks, display conditions, loop blocks, synced sections, multilingual templates
- Comments, mentions, roles and permissions
- White label, custom themes, your own AI model
- Your own storage, self-hosted if you want
- Email builder and landing page builder
Your own editor
$11,332 per developer per month, in salary
- About $68,000 for two developers to reach version one in a quarter
- Inbox preview services from $99 a month
- Every client fix, upgrade and security patch after launch
- Open-source core with no licence fee
Verified on 23 October 2026 against US median developer pay (BLS).
How Topol Plugin bills
Business costs $300 a month for 500 prepaid users and $0.70 per extra user. On your own storage, only users are metered.
What building costs
Open-source cores carry no licence fee. Your bill is salaries, plus inbox preview services from $99 a month for 1,000 previews.
At 1,000 active users on your own storage, Topol Plugin Business costs $650 a month, which is $300 for 500 users plus 500 extras at $0.70. That is $7,800 a year, and two developers on version one for a quarter cost about $68,000 in salary.
Your own email editor has to keep up with email clients that change after launch.
Litmus, an email testing company, found in its own study that the top five email clients made a change every 1.2 days on average.
Reports from any platform
Topol fixes issues that users report on any platform that embeds it. An in-house editor learns only from your own customers' tickets.
New Outlook underlined links
Links appeared underlined in new Outlook until an August 2026 fix. Topol shipped it to platforms through its current loader URL.
New Outlook for Mac
New Outlook for Mac showed content twice that was set to hide on mobile or desktop, until an August 2026 fix.
Yahoo dropped backgrounds
Yahoo dropped a section's background colour or image when both were set, until an August 2026 fix.
A framework release broke
GrapesJS, an open-source editor framework, shipped v0.23.7 without its JavaScript bundles to npm and CDN users. v0.23.8 fixed it a day later.
MJML 6 changes the defaults
MJML 6, in alpha since October 2026, needs Node.js 22, removes tbody and sets a 16px default font size.
Topol's changelog lists 76 fixes in 19 months, each shipped through Topol's loader to the platforms that embed it. An in-house editor ships each of its own fixes alone, after its own customers find the break.
A vibe-coded email editor is version one, a decompiled one is a snapshot, and fixes still come from production.
After ten years of running its editor, Topol has found that the list of fixes comes only from production, with real email clients and real users.
Your prototype is version one
An AI prototype covers the canvas, the part AI writes fastest. Saved templates, uploads, previews and every later fix are still ahead.
AI cannot know your recipients
Topol supports 90+ clients. AI can run a test but cannot know which ones your recipients use or what changes next month.
Your customer finds the break
AI writes a fix once someone reports a break. In production, your customer reports it to your support desk.
The code was never the cost
In Topol's view, the code was never the expensive part. Testing, fixes, feature requests and security continue while users rely on it.
A copy misses every fix
A decompiled Topol Plugin misses every fix after the day it is copied. Topol ships fixes only through its loader URL.
Use AI for the embed
YourPCM, which runs four SaaS products, embedded Topol Plugin with ChatGPT and Topol's docs. It never needed to contact Topol's support.
What each open-source email builder leaves you to build.
Each open-source email builder below gives you an editor core or markup, and storage, inbox testing and client fixes stay with your team.
GrapesJS
GrapesJS is a free BSD-3 web-builder framework with an MJML plugin. Your team adds storage endpoints, roles, test send and inbox testing.
EmailBuilder.js
EmailBuilder.js is an MIT React block editor with no built-in saving or drag and drop. Its JSON to HTML export is one-way.
Maily.to
Maily.to is an MIT block editor with variables, loops and conditions. Storage, roles and version history stay with your team.
Easy Email
Easy Email is an MIT drag-and-drop MJML editor for React 18, and its README says it supports only Chrome.
react-email
react-email is an MIT library for coding emails in React. Its new editor is rich text, and templates live in your code.
Templatical
Templatical is a source-available MJML editor with merge tags, comments and version history. You build its backend, and one developer maintains it.
Mosaico
Mosaico is a GPL-3.0 template-driven editor with one production template. Uploads need your own server, and its docs show no merge tags.
SendWithSES designer
SendWithSES publishes an MIT Angular 15 email designer that writes table HTML without MJML. Uploads go through your callbacks.
MJML
MJML is a free markup language that compiles to responsive HTML. The editor, storage and previews above it are yours to build.
| Route | Licence | Stars | Last release | Type | Output | Still yours to build |
|---|---|---|---|---|---|---|
| Topol Plugin | Per plan from $70 | Updated monthly | Finished white-label editor | HTML via MJML, 90+ clients | Save and comment endpoints, your sender | |
| GrapesJS | BSD-3 | 26,323 | v0.23.8, Oct 2026 | Framework plus MJML plugin | MJML in the browser | Storage, previews, test send, inbox tests |
| EmailBuilder.js | MIT | 1,772 | 0.0.9, Jan 2026 | React block editor | Own HTML | Drag and drop, saving, merge tags |
| Maily.to | MIT | 3,981 | 0.3.7, Feb 2026 | TipTap block editor | react-email HTML | Storage, roles, versions, test send |
| Easy Email | MIT | 3,058 | 4.17.1, Jun 2026 | Drag-and-drop editor | MJML in the browser | Storage, roles, versions, test send |
| react-email | MIT | 19,854 | 6.11.3, Oct 2026 | Code-first components | React to HTML | Drag and drop, storage, roles |
| Templatical | FSL-1.1-MIT | 527 | 0.49.0, Oct 2026 | Drag-and-drop editor | MJML | Backend for storage, comments, versions |
| Mosaico | GPL-3.0 | 1,783 | 0.18.11, Aug 2025 | Template-driven editor | Template HTML | Upload server, merge tags, versions |
| SendWithSES designer | MIT | 2,304 | 0.5.22, Sep 2025 | Angular 15 designer | Table HTML | Storage, roles, versions, test send |
| MJML | MIT | 18,276 | 5.4.1, Sep 2026 | Markup language | Responsive HTML | The whole editor |
Will the emails look right in every inbox?
Once your customers send an email, it has to display correctly in Outlook 2016, Gmail on Android and Apple Mail.
90+ email clients
Templates compile through MJML into HTML that renders correctly in 90+ email clients, old Outlook included. Topol tests the output itself.
Dark-mode preview
Topol Plugin's preview approximates the colour changes clients make in dark mode. Images, gradients and background images stay as they are.
No test round before each send
Topol's case study reports that FLG, a lead-conversion CRM, no longer tests its own marketing emails across clients before each send.
How does integration work?
Your developers install one package, mount the editor with a configuration object and point saving at your own endpoints.
Your framework
Topol ships typed packages for React, Vue, Angular and Svelte, plus a plain script tag. One configuration object mounts the editor.
Your storage
Topol Plugin hosts your customers' images, or serves them from your own S3, Google Cloud or R2 bucket from Expansion at $140.
Your backend
Templates save to your endpoints, and Topol never stores them. Topol's API converts JSON to HTML with no per-call fee.
When building your own email editor makes sense.
Building fits two cases, and each one keeps costing for as long as the editor runs.
The editor is your product
If customers pay for the editor itself, it is your core product. Each developer on it earns a median $135,980 a year.
Output no vendor produces
If your product needs output no vendor's editor produces, embedding cannot deliver it. Your team builds and tests that renderer itself.
Topol Plugin vs building your own email editor, feature by feature.
A checkmark means the feature comes with the $300 Business plan.
| Feature | Topol Plugin $300 a month, 500 users included | Your own editor $11,332 a month per developer, in salary |
|---|---|---|
| Pricing. | ||
| Monthly cost | Business, $300 a month | $11,332 per developer, in salary |
| Users included | 500 prepaid, $0.70 each extra | Unlimited, hosting grows with use |
| Unlimited users | Enterprise from $600 a month | Every route |
| Time to launch | About a week | A quarter for version one |
| Ongoing cost | Plan, extra users, your endpoints | Salaries, inbox previews, every client fix |
| Inbox testing tool | Topol tests the output itself | Preview services from $99 a month |
| Free plan | 14-day trial, no card | No licence fee, salaries still due |
| Editor. | ||
| Drag-and-drop email builder | Yes | Build, or adopt a core |
| Landing page builder | Yes | GrapesJS core, else a separate build |
| Premade templates | Included | Design your own |
| Saved blocks | Yes | Templatical includes it, else build |
| Custom blocks wired to your data | Yes | Build |
| Undo and redo | Yes | Varies, EmailBuilder.js demo lacks it |
| Editor UI languages | 21 built in, more on request | GrapesJS 22, Templatical 8, Easy Email 7 |
| White label | Yes | Your product, your brand |
| Custom themes | Yes | Your own CSS |
| Content features. | ||
| Merge tags in any syntax | Yes | Maily, Easy Email, Templatical include them |
| Display conditions | Yes | Maily and Templatical include it, else build |
| Loop blocks | Yes | Maily includes it, Templatical by tag |
| Multilingual templates | Unlimited languages | Build |
| Synced content | Across all templates | Build |
| Previews and rendering. | ||
| Desktop and mobile preview | Yes | Templatical, Easy Email, EmailBuilder.js include it |
| Dark-mode preview | Yes, an approximation | Templatical includes it, else build |
| Merge-tag preview | Yes | Templatical and react-email's preview server include it |
| Test send | Through your own sender | Templatical's button over your sender, else build |
| Rendering engine | MJML, open source | Your HTML or MJML |
| Email clients rendered | 90+ | Your own test matrix |
| Who reports the breaks | Users on every embedding platform | Your own customers only |
| Inbox fixes when clients change | Shipped by Topol through the loader | Found by your customers, fixed by you |
| Collaboration. | ||
| Comments and mentions | Yes, stored on your endpoints | Templatical has comments, else build |
| Roles and permissions | Yes | Build |
| Autosave and version history | Yes, through your endpoints | Templatical includes it, else build |
| Real-time co-editing | No | Templatical includes it, else build |
| Integration. | ||
| Framework packages | React, Vue, Angular, Svelte, JS | Whatever you write |
| Bring your own storage | Yes | Your storage only |
| Self-hosted editor | No | Yes |
| Templates stored | Your backend | Your backend |
| HTML and JSON export | Yes | Every core exports HTML |
| HTML import | Topol's conversion tool or HTML block | Templatical and GrapesJS import HTML |
| JSON-to-HTML API | Included, no per-call fee | Run the core's renderer yourself |
| Maintenance. | ||
| Editor updates | Shipped by Topol inside the plan | Your team |
| Upload validation | File type checked by leading bytes | Build and patch it yourself |
| Vendor support for your team | Email, business days 9 to 5 CET | GitHub issues, or a paid tier |
| Compliance and hosting. | ||
| EU hosting | Yes | Wherever you host |
| GDPR and CCPA | Yes | Your own policies |
| Sending. | ||
| Email sending | Lettr by Topol, live | Your own backend |
Topol Plugin
$300 a month, 500 users included
Your own editor
$11,332 a month per developer, in salary
Pricing.
Monthly cost
Users included
Unlimited users
Time to launch
Ongoing cost
Inbox testing tool
Free plan
Editor.
Drag-and-drop email builder
Landing page builder
Premade templates
Saved blocks
Custom blocks wired to your data
Undo and redo
Editor UI languages
White label
Custom themes
Content features.
Merge tags in any syntax
Display conditions
Loop blocks
Multilingual templates
Synced content
Previews and rendering.
Desktop and mobile preview
Dark-mode preview
Merge-tag preview
Test send
Rendering engine
Email clients rendered
Who reports the breaks
Inbox fixes when clients change
Collaboration.
Comments and mentions
Roles and permissions
Autosave and version history
Real-time co-editing
Integration.
Framework packages
Bring your own storage
Self-hosted editor
Templates stored
HTML and JSON export
HTML import
JSON-to-HTML API
Maintenance.
Editor updates
Upload validation
Vendor support for your team
Compliance and hosting.
EU hosting
GDPR and CCPA
Sending.
Email sending
See it in your stack.
How to move from your own editor to Topol Plugin.
If you already run your own editor, Topol Plugin runs beside it behind a feature flag until the last template has moved.
Export your templates as HTML
Export HTML from your current editor.
Convert HTML to Topol JSON
Topol provides a tool that converts your HTML templates into Topol JSON. A single template can also go into an HTML block.
Install the package
Add Topol's package for your framework and load the JSON.
Map your features
Map your variables, conditions and repeaters to merge tags, display conditions and loop blocks. Rebuild any custom pieces as custom blocks.
Run both behind a flag
Move one tenant first, then the rest, while your old editor keeps working.
Rough timeline: you have a sandbox on day one and a first tenant within a week, then move the rest over the following two weeks.
Need sending too? Lettr by Topol sends it.
Lettr, Topol's EU-hosted email API and SMTP, sends what your users build in the editor. A home-built editor exports HTML, and sending through your own backend is yours to arrange.
See LettrWhen your own editor fits, and when Topol Plugin does.
Choose your own editor if.
- The editor is the product your customers pay for.
- Your product needs output other than standard email HTML.
- You accept owning every client fix, upgrade and support ticket for as long as the editor runs.
Choose Topol Plugin if.
- You want a finished white-label editor on Business at $300 a month for 500 prepaid users.
- You want every fix Topol ships for any platform to reach yours too.
- You want previews, test send, comments and version history without building them.
- You want your developers on the product your customers pay for.
Embeddable editors to compare.
Beefree SDK
Priced by plan plus API calls, data traffic and hosted rows.
Unlayer
Email, landing pages, popups and documents in one SDK.
Stripo Plugin
Priced by unique emails created or modified each month.
Chamaileon SDK
Priced by monthly active users and generator calls.
GrapesJS Studio SDK
Counts editor sessions, from $0 with a badge to $2,000 on Business.
Build your own email editor FAQ.
Talk to an expertTeams running Topol Plugin.
FLG
No longer tests its own marketing emails across clients before each send, and saves about an hour per template.
Affinect
Never maintains the editor, its responsive behaviour or its email HTML as clients change.
Message34
Saw email-design support requests fall about 30% after replacing its built-in editor.
Customerscore.io
Saved about three months of initial development, and its emails render consistently across devices and email providers.
Pricing and feature sources.
- Topol Plugin pricingtopol.io
- Topol features ledgertopol.io
- Topol home page FAQ, support and integrationtopol.io
- Build or Buy an Email Editor in the Age of AI? (Topol blog)topol.io
- How Topol's editor was first built (Topol blog)topol.io
- Affinect case studytopol.io
- Customerscore.io case studytopol.io
- FLG case studytopol.io
- Message34 case studytopol.io
- YourPCM case studytopol.io
- Editor introduction, iframe and configuration (Topol docs)docs.topol.io
- New loader URL (Topol docs)docs.topol.io
- Previews, top bar (Topol docs)docs.topol.io
- Dark mode preview (Topol docs)docs.topol.io
- Merge tag previews (Topol docs)docs.topol.io
- Sending a test email (Topol docs)docs.topol.io
- Image resizing and compression (Topol docs)docs.topol.io
- Custom storage (Topol docs)docs.topol.io
- Framework packages (Topol docs)docs.topol.io
- Editor interface languages (Topol docs)docs.topol.io
- Multilingual templates (Topol docs)docs.topol.io
- Comments (Topol docs)docs.topol.io
- Roles and permissions (Topol docs)docs.topol.io
- HTML block (Topol docs)docs.topol.io
- JSON to HTML conversion (Topol docs)docs.topol.io
- About the changelog (Topol docs)docs.topol.io
- Topol changelog, July 2025docs.topol.io
- Topol changelog, January 2026docs.topol.io
- Topol changelog, August 2026docs.topol.io
- Topol changelog, September 2026docs.topol.io
- Email client market share (Litmus)litmus.com
- Email testing (Litmus)litmus.com
- Software developers pay (US BLS)bls.gov
- Inbox preview pricingemailonacid.com
- MJMLmjml.io
- MJML on GitHubgithub.com
- MJML 6 alpha release notesgithub.com
- GrapesJS on GitHubgithub.com
- GrapesJS releasesgithub.com
- EmailBuilder.js on GitHubgithub.com
- Maily.to on GitHubgithub.com
- Easy Email on GitHubgithub.com
- react-emailreact.email
- Templatical on GitHubgithub.com
- Mosaico on GitHubgithub.com
- SendWithSES designer on GitHubgithub.com
- Unlayer react-email-editor on GitHubgithub.com
- Lettr email API and SMTPlettr.com
- Topol Plugin pricingtopol.io
- Topol Plugin pricing matrix: Business featurestopol.io
- Topol Plugin overviewtopol.io
- Landing Page Editortopol.io
- Framework packages (docs)docs.topol.io
- Custom storage (docs)docs.topol.io
- JSON to HTML conversion (docs)docs.topol.io
- Topol features ledgertopol.io
- Plugin featurestopol.io
- Plugin Enterprisetopol.io
- Editor interface languages (docs)docs.topol.io
- Multilingual templates (docs)docs.topol.io
- Getting started, user IDs (docs)docs.topol.io
- Image traffic allowance (Topol support)support.topol.io
We read every competitor fact on this page from the sources above on 23 October 2026.
Try it in your stack.
Embed the editor with your own API key today, or book a demo and see it on your own templates first.
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