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Emailens

emailens.dev

From $9/mo Free plan Open source WebAPISelf-hostedBrowser extension
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Spec score 9.4 #1 of 28 in Email Testing Software

What it is

Emailens previews HTML email rendering across 21 email clients and checks compatibility across 298 CSS and HTML features. It scores compatibility from 0 to 100 per client and provides rendered screenshots and simulated dark mode variants. Inputs include HTML, React Email JSX, MJML, and Maizzle. Developers can use a web app, REST API, MCP server, GitHub Action, or standalone @emailens/engine package. Campaign HTML can be imported from a view-in-browser link; Mailchimp URL import is marked verified, while other listed platforms require pasted HTML. Emailens discusses merge tags for Mailchimp, Klaviyo, HubSpot, Braze, and Salesforce Marketing Cloud. The free plan costs nothing and includes 30 simulated previews per day, all 21 clients, one monitored domain, seven-day audit history, and three AI Fixes. Paid plans are Dev at $9 a month, Pro at $19 a month, and Team at $49 a month. Emailens says unsaved previews are processed in memory and authenticated previews and screenshots are purged after 30 days.

Spec sheet

What it does
Emailens previews and audits HTML email rendering across 21 email clients, producing compatibility scores, warnings, dark-mode variants and screenshots.Read 15 Oct 2026 · docs.emailens.dev
Purpose
Emailens previews and checks how HTML emails render across 21 email clients.Read 29 Sep 2026 · docs.emailens.dev
Audience
The pricing page describes the free plan as suited to hobbyists and individual developers, and Dev as built for freelance developers, indie hackers, and creators.Read 29 Sep 2026 · docs.emailens.dev
Integrations
The product offers a web app, REST API, MCP server, GitHub Action, and standalone @emailens/engine package.Read 29 Sep 2026 · docs.emailens.dev
Security
The security page says unsaved previews are processed in memory and authenticated previews and screenshots are automatically purged after 30 days.Read 29 Sep 2026 · emailens.dev
Privacy
The privacy policy says users can sign in with email and password or Google or GitHub, and can request data rights through [email protected].Read 29 Sep 2026 · emailens.dev
Support
The security page says vulnerability reports are acknowledged within 48 business hours.Read 29 Sep 2026 · emailens.dev
Maker
The maker identifies founder and lead engineer Philippe KAM on its About page.Read 15 Oct 2026 · emailens.dev
AI Builder
AI Builder generates HTML, React Email, MJML or Maizzle from a brief and iteratively repairs compatibility issues.Read 15 Oct 2026 · emailens.dev
AI data use
Emailens states that prompts, templates and AI-processed HTML are not used to train foundation models under Anthropic commercial terms.Read 15 Oct 2026 · emailens.dev
AI Fix
AI Fix produces structured repair instructions for compatibility warnings and is limited by plan credits.Read 15 Oct 2026 · emailens.dev
API authentication
Authenticated API calls use an ek_live bearer token or x-api-key header.Read 15 Oct 2026 · docs.emailens.dev
Chrome extension details
The Chrome listing reports version 0.1.0, 13 users, a 70.65 KiB package and developer Sié Philippe Angelo KAM in Montfermeil, France.Read 15 Oct 2026 · chromewebstore.google.com
Chrome rating
The Chrome Web Store lists Emailens: One-Click Email Audit at 5.0 out of 5 from 1 rating.Read 15 Oct 2026 · chromewebstore.google.com
CLI
The CLI provides analyze, preview, export, lint and fix commands with JSON output and CI exit codes.Read 15 Oct 2026 · github.com
Compatibility analysis
It tracks 298 CSS and HTML features and scores compatibility from 0 to 100 per client.Read 29 Sep 2026 · docs.emailens.dev
Compatibility scoring
Each client receives a compatibility score from 0 to 100 with framework-aware fix suggestions.Read 15 Oct 2026 · docs.emailens.dev
Dark mode
Emailens generates simulated dark-mode variants for supported clients.Read 15 Oct 2026 · docs.emailens.dev
Data retention
Unsaved previews are processed in memory, while authenticated previews and screenshots are automatically purged after 30 days.Read 15 Oct 2026 · emailens.dev
Deliverability checks
The API and MCP tools check SPF, DKIM, DMARC, MX and BIMI records.Read 15 Oct 2026 · docs.emailens.dev
Documentation depth
Documentation includes getting started, REST endpoints, MCP setup and tools, client reference, engine APIs, rate limits and GitHub Action guidance.Read 15 Oct 2026 · docs.emailens.dev
Email sandbox
The service provides a non-delivery SMTP relay on port 2525 and generated @try.emailens.dev inboxes for inspecting messages, headers, attachments, OTPs and links.Read 15 Oct 2026 · emailens.dev
Encryption
The security page states that connections use TLS 1.3 and databases and object storage use AES-256 encryption at rest.Read 29 Sep 2026 · emailens.dev
Engine package
@emailens/engine exposes auditEmail and client-specific transformation functions for embedding analysis in JavaScript applications.Read 15 Oct 2026 · github.com
ESP imports
Emailens says it can import campaign HTML from a view-in-browser link; the page marks Mailchimp URL import verified and instructs users to paste HTML for other listed platforms.Read 29 Sep 2026 · emailens.dev
GitHub Action
emailens/action can fail pull requests when email compatibility scores fall below a configured threshold.Read 15 Oct 2026 · github.com
GitHub engine activity
The engine repository shows 15 stars, 2 forks and an MIT license.Read 15 Oct 2026 · github.com
GitHub MCP activity
The MCP repository shows 7 stars, 1 fork and an MIT license.Read 15 Oct 2026 · github.com
GitHub organization
The verified GitHub organization describes Emailens as an email QA SaaS with web app, REST API, MCP server, GitHub Action and CLI repositories.Read 15 Oct 2026 · github.com
GitHub release
The engine repository records release v0.9.6 on July 28, 2026, adding exported severity and issue types while preserving the public API.Read 15 Oct 2026 · github.com
Independent ecosystem signal
TrustMRR categorizes Emailens in developer tools, AI, productivity, SaaS and content creation markets and reports a domain rating of 4/100.Read 15 Oct 2026 · trustmrr.com
Inputs and previews
It accepts HTML, React Email JSX, MJML, or Maizzle and provides simulated dark mode variants and rendered screenshots.Read 29 Sep 2026 · docs.emailens.dev
Installation runtimes
Official installation instructions support Node.js, Bun and Deno, with minimal cheerio and css-tree dependencies.Read 15 Oct 2026 · docs.emailens.dev
Limit: compiler dependencies
MCP compilation for MJML, Maizzle and React Email requires optional packages to be installed where the server runs.Read 15 Oct 2026 · github.com
Limit: hosted MCP screenshots
The remote MCP endpoint does not provide screenshot capture or share-preview tools, which are available through local MCP with an API key.Read 15 Oct 2026 · docs.emailens.dev
Limit: simulation accuracy
The terms disclaim that simulated previews are not guaranteed to match real email clients perfectly or resolve every production rendering issue.Read 15 Oct 2026 · emailens.dev
MCP integration
The MCP server offers local analysis tools and optional hosted screenshot and sharing tools for Claude Desktop, Claude Code, Cursor and other MCP clients.Read 15 Oct 2026 · docs.emailens.dev
Open-source scope
The engine, CLI, MCP server, VS Code extension and GitHub Action are MIT-licensed; the hosted web app and screenshot farm are commercial.Read 15 Oct 2026 · emailens.dev
Privacy and GDPR
The privacy policy says Emailens does not sell personal information and offers JSON export, account deletion and a standard DPA.Read 15 Oct 2026 · emailens.dev
Quality audit
Audits cover CSS compatibility, spam signals, links, accessibility, images, inbox preview, size, template variables and overflow.Read 15 Oct 2026 · github.com
REST API
The REST API exposes preview, share, key management, monitored-domain and deliverability endpoints under emailens.dev/api.Read 15 Oct 2026 · docs.emailens.dev
Security encryption
Emailens states that traffic uses TLS 1.3 and stored PostgreSQL and object data use AES-256 encryption at rest.Read 15 Oct 2026 · emailens.dev
Self-hosting
Local engine, CLI, MCP and editor workflows run without an Emailens account; hosted screenshots and share links require the cloud API.Read 15 Oct 2026 · emailens.dev
Supported ESPs
The integrations page discusses Mailchimp, Klaviyo, HubSpot, Braze, and Salesforce Marketing Cloud merge tags.Read 29 Sep 2026 · emailens.dev
Supported inputs
The engine accepts raw HTML, React Email JSX, MJML and Maizzle templates.Read 15 Oct 2026 · docs.emailens.dev
Tracked rules
The documentation says Emailens tracks 298 CSS and HTML features across its 21-client matrix.Read 15 Oct 2026 · docs.emailens.dev
VS Code extension
The VS Code extension runs the engine locally for lint-as-you-type diagnostics, client-specific previews and quick fixes.Read 15 Oct 2026 · github.com

Plans and prices

Free Free forever 30 previews/day · all 21 clients · standard audit · 3 lifetime AI Fixes · 1 monitored domain · 7-day audit history · MCP tools Read 15 Oct 2026 · docs.emailens.dev
Free Free $0 forever 30 simulated previews/day · all 21 email clients · 1 monitored domain · 7-day audit history · 3 AI Fixes Read 29 Sep 2026 · emailens.dev
Dev $9 a month monthly; $90/year annually 100 previews/day · full audit · 3 AI Builder runs/month · 10 AI Fixes/month · 1 API key · 3 monitored domains · 30-day history · share links and diffs Read 15 Oct 2026 · docs.emailens.dev
Dev $9 a month $9/mo; $90 a year 100 simulated previews/day · 1 API key · 3 monitored domains · 30-day audit history · 10 AI Fixes/month · 3 Builder runs/month Read 29 Sep 2026 · emailens.dev
Pro $19 a month $19/mo; $180 a year Unlimited previews · 10 API keys · 10 monitored domains · 1-year audit history · CI/CD and GitHub Action · 30 Builder runs/day Read 29 Sep 2026 · emailens.dev
Pro $19 a month monthly; $180/year annually Unlimited previews · 30 AI Builder runs/day · 10 API keys · 10 monitored domains · 365-day archive · pre-send gate · CI/CD and GitHub Action Read 15 Oct 2026 · docs.emailens.dev
Team $49 a month monthly; $490/year annually Unlimited previews · 100 AI Builder runs/day · 10 API keys · 10 monitored domains · 365-day archive · centralized billing · high-throughput MCP Read 15 Oct 2026 · docs.emailens.dev

Every Emailens plan and price →

Strong points and limits

Strong points

  • Checks rendering across 21 email clients.
  • Accepts HTML, React Email JSX, MJML, and Maizzle.
  • Offers REST API, MCP server, and GitHub Action.
  • Free plan includes 30 previews per day.

Limits

  • Mailchimp is the only verified URL import.
  • Free plan limits previews to 30 per day.
  • Paid plans start at $9 a month.

Who it suits

The free plan is described as suited to hobbyists and individual developers. Dev is aimed at freelance developers, indie hackers, and creators; the API and CI options may suit developers integrating checks into their workflow.

Verdict

Emailens combines client previews with compatibility scoring and several developer integrations. Its free plan has daily and history limits; paid plans add higher allowances and capabilities.

Where Specifiction places it

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