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Customer.io alternatives · Email Marketing

Open-source alternatives to Customer.io

Customer.io is not described as open source on its own site. 4 of the 57 other email marketing and newsletter tools in this directory are open source, according to their own sites.

Customer.io is a paid product with a free trial, starting at $100 per month for up to 5,000 profiles, billed monthly. 2 of them are free or have a free plan.

4 tools · Listings checked up to Nov 12, 2026 · Where the facts come from

How each one differs from Customer.io

  1. Mautic

    Open source marketing automation you can self-host

    • Mautic starts at €247.50 per month, billed annually (€275 billed quarterly). Customer.io starts at $100 per month for up to 5,000 profiles, billed monthly.
    • Mautic has a free plan. Customer.io does not, though it has a free trial.
    • Mautic is open source and self-hostable, according to its own site.
    • Customer.io also covers business texting.
    Mautic pricing and details

  2. listmonk

    Free self-hosted newsletter and mailing list manager

    • listmonk is free. Customer.io starts at $100 per month for up to 5,000 profiles, billed monthly.
    • listmonk has a free plan. Customer.io does not, though it has a free trial.
    • listmonk is open source and self-hostable, according to its own site.
    • listmonk also covers transactional email.
    listmonk pricing and details

  3. Groundhogg

    Flat-rate CRM and email marketing plugin for WordPress

    • Groundhogg starts at $20 per month for 1 site, billed annually ($240). Customer.io starts at $100 per month for up to 5,000 profiles, billed monthly.
    • Groundhogg is open source and self-hostable, according to its own site.
    • Groundhogg also covers sales pipeline and AI agents.
    • Customer.io also covers business texting.
    Groundhogg pricing and details

  4. Ghost

    Open source publishing with newsletters and paid memberships

    • Ghost starts at $15 per month for up to 1,000 members, billed yearly ($18 billed monthly). Customer.io starts at $100 per month for up to 5,000 profiles, billed monthly.
    • Ghost is open source, according to its own site.
    • Ghost also covers paid newsletters.
    • Customer.io also covers marketing automation and business texting.
    Ghost pricing and details

Common questions

Is there an open-source alternative to Customer.io?

Yes. Mautic, listmonk, Groundhogg and Ghost are open source, according to their own sites.

Is Customer.io open source?

Customer.io is not described as open source on its own site. The listing was checked on Oct 17, 2026 against the pages it cites.

Which of these email marketing and newsletter tools are free?

Mautic and listmonk are free or have a free plan.

When was this checked?

Each listing shows its own date. On this page they run from Oct 17, 2026 to Nov 12, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Customer.io: the alternatives its listing names first, then the tools that share the most features with it.