Updated September 28, 2026
Keila
Plunk

Keila vs Plunk

open-source email newsletter tool with EU hosting vs open-source modern email platform

8
Features Compared
3
Key Differences
8
FAQs Answered
TL;DR

Keila ($8-32/month (cloud)) is a open-source email newsletter tool with EU hosting. Plunk (Free tier, then usage-based) is a open-source modern email platform. Keila wins on open source (agplv3). Plunk wins on open source. For SaaS founders, Sequenzy ($49/mo) offers Stripe integration and AI sequences that neither provides.

Platform Overview

See how each platform looks

Keila

Keila dashboard screenshot

Open-source email newsletter tool with visual editor, API, and self-hosted or EU cloud hosting options.

Plunk

Plunk dashboard screenshot

Open-source email platform for transactional, marketing, and automated emails with simple pricing.

Key Differences

The main things that set these tools apart

Pricing model
Tie

Keila costs $8-32/month (cloud). Plunk costs Free tier, then usage-based. Different pricing models for different needs and budgets.

Primary use case
Tie

Keila is best for open source (agplv3). Plunk is best for open source. They optimize for different goals.

Feature depth
Tie

Keila strengths: Open source (AGPLv3), EU cloud hosting, Visual editor + MJML. Plunk strengths: Open source, Modern stack, Transactional + marketing.

Pricing Comparison

At comparable usage

Keila
$8-32/month (cloud)

Open source (AGPLv3). Self-hosted free. EU cloud.

Visit Keila
Plunk
Free tier, then usage-based

Open source. Modern stack. Transactional + marketing.

Visit Plunk
Best for SaaS
Sequenzy
$49/month

At comparable usage

60,000 emails/mo, unlimited contacts.

Free plan: up to 2,500 emails/month. Paid plans from $19/month (15,000 emails), unlimited contacts on every plan. See all plans

Start for free

Feature Comparison

8 features compared side-by-side

Feature
Keila
Plunk
Sequenzy
Core Features
Open source (AGPLv3)
Varies
Open source
Varies
Email API
Visual email editor
Full drag-and-drop
Marketing & Automation
Marketing automation
Basic
AI-powered sequences
Subscriber management
Full lifecycle management
Stripe integration
Native
Transactional email

API, CLI and MCP: How AI-Ready Is Each Tool?

What you, or an AI assistant like Claude or ChatGPT, can do in each tool without opening the dashboard. “MCP” means the vendor's own MCP server can do it. Each status links to the doc that confirms it.

Plunk
MCP server
Official, read and writeRuns locally

@plunk/mcp in vendor repo, stdio via npx, hosted or self-hosted. Read-only mode optional; sends need confirmation.

MCP docs
CLINoneAPIREST
Through its MCP (10 of 14)

Create and update contacts, Create segments, Create campaigns, Send or schedule campaigns, Trigger automations, Create and edit templates, Send transactional email, Read campaign analytics, View or manage unsubscribes, Set up sending domains

API only

Add contacts to lists or tags, Build automations

Checked September 28, 2026
Sequenzy
MCP server
Official, read and writeHosted or local

250+ tools. Hosted with OAuth or local with an API key.

MCP docs
CLIOfficialAPIREST
Through its MCP (14 of 14)

Create and update contacts, Add contacts to lists or tags, Create segments, Create campaigns, Send or schedule campaigns, Build automations, Trigger automations, Create A/B tests, Create and edit templates, Send transactional email, Read campaign analytics, View or manage unsubscribes, Set up sending domains, Create forms or landing pages

Checked September 28, 2026

If You Leave Later: What You Can Take With You

Switching is easier when your data comes with you. Unsubscribes matter most: without them, people who opted out get emailed again.

Plunk
Contacts and custom fields
Yes

API GET /contacts (cursor pagination, max 100 per page) with custom data

Plunk docs
Unsubscribes and bounces
Not confirmed

Contacts carry a subscribed flag via API; no dedicated suppression export documented

Plunk docs
Templates as HTML
Yes

API GET /templates returns template body HTML

Plunk docs
Automations
Not confirmed

Workflows are managed via API; no export format documented. Self-hosters have direct DB access.

Open and click history
Not confirmed

Campaign stats via API; per-contact event export not documented

Sequenzy
Contacts and custom fields
Yes

Subscribers > Export downloads a CSV with status, tags and custom attributes, or page through GET /subscribers

Sequenzy docs
Unsubscribes and bounces
Yes

Unsubscribed and bounced contacts carry their status in the CSV export, and GET /suppressions lists them

Sequenzy docs
Templates as HTML
Yes

GET /templates/{id}/render returns the exact email-safe HTML that is sent

Sequenzy docs
Automations
Yes

GET /sequences/{id} returns each sequence's steps, delays and conditions as JSON; other tools cannot import it directly

Sequenzy docs
Open and click history
Yes, on request

Full per-contact open and click history is exported on request; opens and clicks also stream out through webhooks as they happen

Pros & Cons

Honest strengths and weaknesses of each platform

Keila

Pros
  • Fully open-source under AGPLv3 license
  • EU cloud hosting for GDPR compliance
  • Self-hosting option for complete data control
  • Extremely affordable cloud pricing at $8-32/month
  • Built with Elixir for reliable performance
  • No vendor lock-in with open-source code
Cons
  • Smaller community and fewer resources
  • Fewer integrations than established platforms
  • Self-hosting requires technical expertise
  • Less sophisticated automation capabilities
  • Limited template selection
  • Newer platform with shorter track record

Plunk

Pros
  • simple AWS SES integration
  • More established platform with larger community
  • Professional support and documentation
  • Regular updates and feature development
  • Broader integration ecosystem
  • Easier setup without technical requirements
Cons
  • Very basic features and automation
  • No open-source option for self-hosting
  • Data stored on vendor servers
  • Less control over email infrastructure
  • Vendor pricing can change without notice
  • Dependent on third-party platform availability

Best For

When to choose each tool

Choose Keila if you...
  • Open source (AGPLv3)
  • EU cloud hosting
  • Visual editor + MJML
  • Privacy-first
Choose Plunk if you...
  • Open source
  • Modern stack
  • Transactional + marketing
  • Developer-friendly

Why Consider Sequenzy Instead

Built for SaaS

Neither Keila nor Plunk offers native Stripe integration. Sequenzy connects to Stripe and triggers emails based on subscription events automatically.

Marketing + transactional unified

One platform for campaigns, transactional emails, and AI sequences. No stitching tools together.

AI-powered sequences

Describe what you want and Sequenzy generates the email sequence. Neither Keila nor Plunk has AI content generation.

Simple pricing

$99/month for 120,000 emails with unlimited subscribers. Check pricing for details.

Overview

Keila and Plunk serve different needs in the email space. Keila is a open-source email newsletter tool with EU hosting. Plunk is a open-source modern email platform.

The choice depends on what you need: open source (agplv3) (Keila) or open source (Plunk). For SaaS businesses specifically, Sequenzy offers purpose-built features that neither tool provides.

Pricing Comparison

  • Keila: $8-32/month (cloud) - Open source (AGPLv3). Self-hosted free. EU cloud.
  • Plunk: Free tier, then usage-based - Open source. Modern stack. Transactional + marketing.
  • Sequenzy: $99/month for 120,000 emails, unlimited subscribers, fully managed. See pricing.

Where Keila Wins

Open source (AGPLv3)

Keila offers open source (agplv3), which is a genuine advantage for teams that need it.

EU cloud hosting

Keila offers eu cloud hosting, which is a genuine advantage for teams that need it.

Visual editor + MJML

Keila offers visual editor + mjml, which is a genuine advantage for teams that need it.

Privacy-first

Keila offers privacy-first, which is a genuine advantage for teams that need it.

Where Plunk Wins

Open source

Plunk offers open source, which matters for teams that prioritize this.

Modern stack

Plunk offers modern stack, which matters for teams that prioritize this.

Transactional + marketing

Plunk offers transactional + marketing, which matters for teams that prioritize this.

Developer-friendly

Plunk offers developer-friendly, which matters for teams that prioritize this.

Open-Source vs Commercial Trade-off

Keila's AGPLv3 license gives you the full source code, the right to modify it, and the option to self-host on your own infrastructure with no dependency on a vendor. Plunk's plans run on its own servers with a free tier before usage-based pricing kicks in, and its feature set stays comparatively basic with fewer self-hosting options. If controlling where the code runs matters to you, Keila is the one built for that.

EU Data Sovereignty

Self-hosted Keila keeps subscriber data on infrastructure you choose, and its EU cloud plan gives GDPR-minded teams a managed option without giving up regional hosting. Plunk stores data on its own servers under its usage-based plans, which works fine for most teams but leaves less control over where records live compared to running Keila yourself.

The Self-Hosting Reality

Self-hosting Keila means you're responsible for the server, updates, and backups, which is worth it mainly for teams with some technical capacity. Plunk removes that operational work through its free tier and usage-based cloud plans, though its feature set is comparatively basic. The right call depends on whether your team would rather manage infrastructure or accept fewer features in exchange for not managing it.

Use-case matchups

Situation Best first look Why
Team wants open-source newsletter control and EU hosting Keila Keila is stronger for privacy, self-hosting, and newsletter management.
Developer wants a modern open-source transactional/marketing API Plunk Plunk is more API-first and lighter for developer workflows.
Organization needs visual newsletter editing Keila Keila has more newsletter-oriented editing than Plunk.
Product team wants simple API-triggered email Plunk Plunk is closer to email infrastructure than a traditional newsletter tool.
SaaS team needs Stripe-aware lifecycle email Sequenzy Sequenzy adds managed billing-triggered lifecycle flows.

Best Fit by Newsletter Control and Developer Email API

Best open-source newsletter tool for EU-hosted campaigns

Choose Keila when the team wants privacy-first newsletter management, visual templates, EU hosting options, and the ability to self-host if needed. It is the better fit when the main job is subscriber campaigns rather than building an email API layer into a product.

Best open-source email API for product-triggered messages

Choose Plunk when developers want a modern API, event-triggered sends, transactional-style workflows, and a lighter product-email layer. It is stronger when messages originate from application events and the team needs infrastructure more than a newsletter editor.

Best managed SaaS email platform for lifecycle automation

Choose Sequenzy when the team wants product-triggered email, transactional templates, campaigns, and Stripe lifecycle automation without operating open-source infrastructure. It is more relevant when billing and customer lifecycle context should drive the whole email program.

Pricing reality

Keila's low cloud pricing or self-hosted option should be weighed against hosting, SMTP, DNS, backups, updates, and deliverability ownership.

Plunk's free tier and usage-based model should be checked against send volume, self-hosting needs, maturity, documentation, template workflow, and whether its marketing features are enough.

Sequenzy's $49/month price is relevant when managed SaaS lifecycle and transactional email matter more than open-source infrastructure control.

Review signals

Platform What reviews in this page suggest What to validate
Keila Review themes favor self-hosting, GDPR control, EU hosting, and open-source newsletters. Confirm technical ownership, automation limits, and integration needs.
Plunk Review themes favor developer-friendly API, modern stack, open-source direction, and simpler setup. Confirm maturity, reliability, documentation, and missing editor/automation features.

Migration checklist

Workstream Moving toward Keila Moving toward Plunk Moving toward Sequenzy
Infrastructure Configure cloud/self-hosted app, SMTP, DNS, backups, updates, and monitoring. Configure cloud/self-hosting, domains, API keys, webhooks, templates, and sending rules. Configure domains, Stripe, app events, transactional routes, and subscriber sync.
Contacts Import subscribers, lists, fields, consent, and suppressions. Import contacts, metadata, suppressions, and template variables. Import subscribers, attributes, tags, suppressions, and billing identifiers.
Automations Keep automation simple or externalize workflow logic. Rebuild API-triggered transactional and marketing sends. Rebuild onboarding, billing, transactional, lifecycle, and campaign flows.
Templates Recreate newsletters, MJML/editor templates, and forms. Recreate API templates and minimal campaign assets. Recreate lifecycle and transactional templates.
Reporting Track campaigns, bounces, unsubscribes, and delivery health. Track API delivery, events, bounces, and campaign basics. Track lifecycle, billing, transactional, and campaign reporting.

Decision checklist

  • Is this a newsletter product decision or an email API decision?
  • Which open-source model better matches your team?
  • Who owns hosting and deliverability?
  • Is Plunk mature enough for your production use case?
  • Would managed SaaS lifecycle email be simpler than either?

Frequently Asked Questions

8 questions answered about Keila vs Plunk

Testimonials

Sequenzy Testimonials

Yusuke

Yusuke

Founder, LandingBoost

It’s the first tool where I’m actually willing to keep working on email without it turning into one giant scary blast. Favorite part is still what I said, being able to split stuff. Drafts vs campaigns vs a single-person send. I can park a lot of “don’t send this yet” work with labels and not feel like it’s one click away from going to everyone. Sequences later. Consent / lists first. I’m slow on purpose.

Rakesh Reddy

Rakesh Reddy

Founder, CrawlRaven

We used Sequenzy to replace a generic onboarding flow with coordinated lifecycle journeys covering signup, connecting Google Search Console, discovering SEO opportunities, upgrading, and paid-customer retention. Event triggers, conditional branches, personalization, and enrollment cancellation gave us precise control over who receives each message - and when someone should exit a journey. We backfilled eligible users into the appropriate journeys. The initial emails went out without bounces, complaints, suppressions, or unexpected recipients. Future users now enter the relevant journeys automatically based on their activity in CrawlRaven.

Elvis Sun

Elvis Sun

Founder, PressPulse & Medialyst

Codex basically one-shotted the migration for syncing our audience from SendGrid to Sequenzy. Sequenzy is fully observable, so agents can just set everything up. The net impact is saving $45/mo, plus 2 hours of my time every time I need to repurpose a newsletter. That's 8 hours a month. My consulting rate is $550/hr, so every hour automated is super valuable.

Caden Sumner

Caden Sumner

Solo founder, Moxie Docs

Lifecycle email was the kind of thing I knew I would need eventually, but have never had to build it out myself and had no idea where to start. In literal hours I had a fully working (but basic) flow for onboarding new users, detecting churn, and re-engaging people who have trials lapsing to hopefully convert. Sequenzy let me offload the entire “keep users engaged and recover the ones who are slipping” workflow to something that just runs. Every hour I'd have spent building and babysitting lifecycle emails went into shipping the actual product instead.

Louis

Louis

Founder

Easy migration from another tool. Premium customer service and easy to set everything up

Apr 9, 2026

Jim

Jim

Founder, FixMyLanding

It helped me grow to $100 MRR, get #1 on Uneed, make more sales, get acquired. I literally love Sequenzy, it's so simple, I love the dashboard. I also saw the integrations and was shocked. 3 sales today, all thanks to Sequenzy. Honestly, thanks.

King Killers

King Killers

Shopify App Store review

Loving the Sequenzy app so far due to the affordability and large subscriber limits. Planning on this becoming my main email app. Campaign + flows setup with the help of their AI took less than 30 minutes.

Verified User

Verified User

Computer Software

SaaS-focused feedback, fast processing, and plenty of integrations. It is very SaaS-focused, supports a wide range of integrations, and processes feedback right away.

Jun 17, 2026

G2
Filip Panoski

Filip Panoski

Founder, Bazzly

I've used 2 other email marketing tools. They were supposedly "market leaders". Both were clunky, unnecessarily expensive and horrible support. When I tried Sequenzy I thought there'd be trade-offs compared to the others. But there weren't, it had everything I needed, there was no bloat, emails delivered extremely fast, and the founders shipped anything I asked in a day. The best part is that Sequenzy is AI native, I rarely do stuff in the dashboard, just use my AI to create campaigns, sequences and segment customers which saves me a ton of time. Never been happier with an email marketing tool.

Max Eccles

Max Eccles

Founder, InstantInterior AI

$600 revenue in 30d from email automations. Very happy I migrated to Sequenzy. Before I was making zero from email automations.

Leo

Leo

Maintainer, Email SDK

Sequenzy's most powerful feature is probably those campaigns. It seems useless at first but they are one of the most important things to send to your users. I get to talk to my users 1:1 and help them set it up for their use case. The owner is really active on X, really nice and helpful. He's the type of person to go out of his way to help you, so you get really good support!

Viraj

Viraj

Founder, SnapCount

After using Loops and Resend, I was looking for an email infrastructure service that had MCP support, Affonso and Dodo Payments integrations, and was affordable. Came across Sequenzy, and the support from Nic has been unbelievable. Migration was done in 24 hours without any issues, and I can run all of my products from a single account.

Jim

Jim

Founder

I run a SaaS, and found Nic on X where I kept seeing posts about his email marketing tool, Sequenzy. I decided to try it for email marketing. Literally on the first day, I used it to send a marketing campaign and I got 5 sales. What I like most is the ai assistant because it actually writes emails that feel real instead of the usual ai slop chatgpt returns, so they do not end up in spam. It also has a 2.5k free email limit which is way better than most tools that only give you around 1k. The best part though is that it handles everything for me, tags, subscribers, sequences and all of it. Without it i would probably be managing a database and a bunch of cron jobs just to make email automation work. Sequenzy just makes my life a lot easier. it can also be set up with 2-3 clicks! Give it a try!!

Mar 10, 2026

Dhiva Logu

Dhiva Logu

Founder

I love everything about Sequenzy and also the kind of support I get from Nic. It's already the best choice for campaigns & Sequences. Specially the integrations with payment providers, auth providers & analytics etc.. is really spot on. Best in terms of features & pricing in the email segment 100% recommend it for SaaS emails :)

Mar 10, 2026

Petros

Petros

Shopify App Store review

The setup was fast and simple. It synced customer, product, and order data quickly. Generating automated flows was simple, and it improved my monthly bottom line by about 7%.

Not sure which to pick?

If you're a SaaS founder who needs Stripe integration and unified email, try Sequenzy free. No credit card required.

Related Comparisons

Written by Sequenzy, which appears in this comparison. How we compare tools

Sequenzy pricing reference

Sequenzy - Complete Pricing Guide

Pricing Model

Sequenzy uses email-volume-based pricing. You only pay for emails you send. Unlimited contacts on all plans — storing subscribers is always free.

All Pricing Tiers

  • 2.5k emails/month: Free (Free annually)
  • 15k emails/month: $19/month ($205/year annually)
  • 30k emails/month: $29/month ($313/year annually)
  • 60k emails/month: $49/month ($529/year annually)
  • 120k emails/month: $99/month ($1069/year annually)
  • 300k emails/month: $199/month ($2149/year annually)
  • 600k emails/month: $399/month ($4309/year annually)
  • 900k emails/month: $599/month ($6469/year annually)
  • 1.2M emails/month: $799/month ($8629/year annually)
  • 2M emails/month: $1299/month ($14029/year annually)
  • 3M emails/month: $1999/month ($21589/year annually)
  • 4M emails/month: $2499/month ($26989/year annually)
  • 5M emails/month: $2999/month ($32389/year annually)
  • Unlimited emails/month: Custom pricing (Custom annually)

Yearly billing: All plans offer a 10% discount when billed annually.

Free Plan Features (2,500 emails/month)

  • Visual automation builder
  • Transactional email API
  • Team and agent inbox
  • Landing pages
  • Unlimited team members
  • Goal tracking & revenue attribution
  • Unlimited lists and segments
  • Payment integrations
  • API, MCP, and CLI access
  • Unlimited sending domains
  • SPF, DKIM, and DMARC
  • Deliverability monitoring
  • Send time optimization
  • A/B testing

Paid Plan Features (15k - 5M emails/month)

  • Visual automation builder
  • Transactional email API
  • Team and agent inbox
  • Landing pages (Create hosted signup pages and attach a custom domain.)
  • Unlimited team members
  • Goal tracking & revenue attribution
  • Unlimited lists and segments
  • Payment integrations (Stripe, Paddle, Lemon Squeezy)
  • API, MCP, and CLI access
  • Unlimited sending domains
  • SPF, DKIM, and DMARC
  • Deliverability monitoring
  • Send time optimization
  • A/B testing

Enterprise Plan Features (Unlimited emails)

  • Visual automation builder
  • Transactional email API
  • Team and agent inbox
  • Landing pages
  • Unlimited team members
  • Goal tracking & revenue attribution
  • Unlimited lists and segments
  • Payment integrations
  • API, MCP, and CLI access
  • Unlimited sending domains
  • SPF, DKIM, and DMARC
  • Deliverability monitoring
  • Send time optimization
  • A/B testing

Important Pricing Notes

  • You only pay for emails you send — unlimited contacts on all plans
  • No hidden fees - all features included in the price
  • No credit card required for free tier

Contact

  • Pricing Page: https://sequenzy.com/pricing
  • Sales: hello@sequenzy.com