What email clients does Emailens support?

Emailens previews across 21 email clients that cover 95%+ of real email opens: Gmail (Web, Android, iOS), Outlook (365, New, Classic, iOS, Android, Mac), Apple Mail (macOS, iOS), Yahoo Mail (Web, Android, iOS), Samsung Mail, Thunderbird, HEY Mail, Proton Mail, AOL Mail, Fastmail, and Superhuman.

What email frameworks does Emailens work with?

Emailens works with React Email, MJML, Maizzle, and raw HTML. It generates framework-native fix snippets so you get fixes in the same syntax you're already writing.

Can Emailens generate emails with AI?

Yes. The AI Builder lets you describe an email in plain English and generates the code in React Email, MJML, Maizzle, or HTML, then repairs its own output across 21 clients until it scores well. You refine it in chat and send it to your dashboard. AI Fix turns compatibility warnings on your own code into a ready patch. AI Fix is free to try (3 fixes); the AI Builder is a taste on the Dev plan (3 builds/month) and included on Pro (30 builds/day).

How much does Emailens cost compared to Litmus?

Emailens starts at $0/month (Free, 30 previews/day), $9/month (Dev, 100 previews/day with API access), and $19/month (Pro, unlimited). Litmus starts at $500/month. Emailens is built specifically for developers, not enterprise marketing teams.

Is Emailens open source?

The core engine (@emailens/engine), MCP server (@emailens/mcp), and CLI (@emailens/cli) are open source and published on npm. You can use them standalone or through the web app.

Can I use Emailens in my CI/CD pipeline?

Yes. Emailens offers a REST API, a GitHub Action, an MCP server, and a CLI tool for CI/CD integration. The Pro plan includes full CI/CD pipeline support.

Open-source core, runs in your editor, CLI, and CI

You write the email.
21 clients rewrite it.

Emailens is the rendering linter for email, the check between building and shipping. It catches exactly what breaks across Gmail, Outlook, Apple Mail, and 18 more (95%+ of real opens), and gives you framework-native fix snippets for React Email, MJML, and Maizzle, in your editor, your CLI, and your CI.

30 seconds to your first preview

Preview Your Email Build with AI

Free plan, 30 previews/day. Or describe an email and let AI build it.

Live Demo

The gap between your design and the inbox

Left: what you built. Right: what your users see. Switch clients to compare.

spoiler: it's Outlook

Showing 7 of 21 supported clients, covering 95%+ of email opens.

Your design

What Gmail renders

16 warnings

gmail-web strips "gap" from styles. Use padding/margin on child elements instead of gap.gap

gmail-web strips "background" from styles. "background" is not supported in this email client.background

gmail-web strips "position" from styles. Use table-based positioning instead of CSS position.position

gmail-web strips "box-shadow" from styles. Use border styling as an alternative to box-shadow.box-shadow

+12 more. See full report

Try with your own email

AI Builder

Describe the email. AI builds it, then makes it render.

Not just another generator. Emailens writes the code in your framework, then repairs its own output across 21 clients until it actually scores, catching what other AI tools ship broken.

AI Builder

From a sentence to a shippable email

Describe it in plain English. Emailens generates React Email, MJML, Maizzle, or HTML, self-heals across every client, and you refine it in chat, then send it straight to your dashboard.

Build with AI

Generates in React Email, MJML, Maizzle, or HTML

Self-heals across 21 clients until the score clears

Refine in chat, target a specific region to change

Send any build to your dashboard in one click

AI Fix: turns compatibility warnings into a ready patch

Match a design: drop in a screenshot, get code that matches

AI Fix is free to try (3 fixes). The AI Builder is a taste on Dev (3 builds/mo) and included on Pro (30/day).

How it fits

One step in the workflow you already have

Emailens doesn't replace React Email, MJML, or Maizzle. It's the check between building and shipping.

Build

Write your email in React Email, MJML, Maizzle, or raw HTML. Whatever fits your project.

Preview

Paste your source into Emailens. See exactly how 21 clients render it, including dark mode.

Fix & ship

Act on actionable, framework-native fix snippets. Ship knowing every inbox looks right.

Beyond rendering

One preview catches more than CSS bugs

Every preview also runs spam analysis, link validation, accessibility checking, image optimization, content-overflow detection, and visual-bug checks, included on all plans.

Spam scoring

Heuristic content analysis: flags excessive caps, missing unsubscribe links, image-heavy layouts, CAN-SPAM address checks, and 15+ other signals.

Link validation

Catches broken hrefs, insecure HTTP links, empty mailto addresses, broken anchors, and generic "click here" anchor text.

Accessibility audit

Checks color contrast, missing alt text, heading hierarchy, lang attributes, and table semantics.

Image analysis

Flags missing dimensions, oversized files, tracking pixels without alt text, and images that break layouts.

Domain authentication

Validates SPF, DKIM, DMARC, MX, and BIMI records so your emails actually reach the inbox, not the spam folder.

Inbox preview

Analyzes subject lines and preheader text with per-client truncation limits. Detects Gmail clipping before your readers do.

Content overflow

Catches fixed-width tables and unbreakable strings that blow past the 600px email boundary and force horizontal scroll on mobile.

Visual bugs

Flags gradients with no background-color fallback and custom fonts with no web-safe stack, before Outlook renders them blank.

Template variables

Catches unresolved merge tags , Handlebars {{var}}, Mailchimp *|TAG|*, AMPscript %%tag%% , left in text or href/src/alt attributes before they ship as raw placeholders.

Open Source

The engine is open source

The core packages that power Emailens are published on npm and open on GitHub. Use them standalone or through the web app.

@emailens/engine

250+ CSS properties across 21 clients, compatibility scoring, dark mode simulation, DNS deliverability checking (SPF/DKIM/DMARC), and spam scoring analysis.

npm GitHub

@emailens/mcp

MCP server with 9 tools: analyze, preview, audit, fix, diff, deliverability, screenshots, and sharing. Works with Claude, Cursor, or any MCP-compatible AI assistant.

npm GitHub

@emailens/cli

Preview, analyze, and lint emails from the terminal. CI/CD-friendly lint command with structured exit codes. Pipe HTML in, get a compatibility report out.

npm GitHub

Read the docs

New

Figma plugin

Design in Figma? Preview how your email renders in 21 clients, directly inside Figma. Select a frame, click preview, get per-client scores and CSS warnings.

Learn moreFree to use

21 email clients, light + dark mode

Per-client compatibility scores (0–100)

CSS warnings with client references

Copy email-safe HTML to clipboard

Share preview links with your team

Works offline: CSS analysis without network

MCP Server

Works with your AI assistant

Drop Emailens into Claude Desktop, Cursor, or any MCP-compatible tool. Analyze emails, fix compatibility issues, capture screenshots, all without leaving your editor.

claude mcp add emailens
| or
npx -y @emailens/mcp

Learn more

Analyze CSS compatibility across 21 clients

Generate fix prompts for Outlook, Gmail, etc.

Compare before/after with diff scoring

Check SPF, DKIM, DMARC deliverability

Capture real screenshots (with API key)

Create shareable preview links

Pricing

Simple, transparent pricing

No per-seat fees. No annual lock-in. Cancel anytime.

Each preview renders across all 21 clients. Competitors charge per client.

Litmus $500/moEmail on Acid $74/moParcel $29+/moEmailens $9/mo

Free

For early adopters

$0forever

30 previews per day
All 21 email clients
CSS compatibility report
Dark mode preview
3 AI Fixes to try
MCP server · 7 local tools

Start Free

Dev

For solo developers

$9/mo

100 previews per day
All 21 email clients
AI Fix · 10/mo + AI Builder · 3 builds/mo
Full API access
Share links & Visual Diff
Size, template & deliverability checks
MCP screenshots + sharing

Start Building

Pro

For teams shipping emails

$19/mo

Unlimited previews
AI Fix + AI Builder · 30 builds/day
CI/CD + GitHub Action
MCP unlimited screenshots
Team workflows
Everything in Dev

Go Pro

Cancel anytime. Upgrade or downgrade in one click.

You write the email.21 clients rewrite it.

The gap between your design and the inbox

Describe the email. AI builds it, then makes it render.

From a sentence to a shippable email

One step in the workflow you already have

Build

Preview

Fix & ship

One preview catches more than CSS bugs

Spam scoring

Link validation

Accessibility audit

Image analysis

Domain authentication

Inbox preview

Content overflow

Visual bugs

Template variables

The engine is open source

@emailens/engine

@emailens/mcp

@emailens/cli

Figma plugin

Works with your AI assistant

Simple, transparent pricing

Free

Dev

Pro

The email CSS thing I fixed this week

You write the email.
21 clients rewrite it.