Building a WordPress Newsletter Plugin Benchmark from the WordPress.org API

Most “best WordPress newsletter plugin” lists mix install counts, ratings, pricing, and vendor claims without saying when the data was checked.

I built a small benchmark from the WordPress.org plugin API to make the comparison reproducible. The raw data is public, the fields are explicit, and the snapshot date is part of the dataset.

Why use the WordPress.org API?

The API gives a consistent snapshot for plugins listed on WordPress.org:

active installs
rating (0–100)
number of ratings
current version
last updated date
required WordPress version
required PHP version

That is enough to compare adoption, maintenance, and environment requirements without scraping marketing pages.

Fetching one plugin

curl -s 'https://api.wordpress.org/plugins/info/1.2/?action=plugin_information&request[slug]=mailpoet'

The response includes active_installs, rating, num_ratings, version, requires, and requires_php.

A small Python collector:

import json import urllib.parse import urllib.request slugs = ["mailpoet", "newsletter", "fluent-crm", "mailchimp-for-wp"] for slug in slugs: query = urllib.parse.urlencode({ "action": "plugin_information", "request[slug]": slug, }) url = f"https://api.wordpress.org/plugins/info/1.2/?{query}" with urllib.request.urlopen(url) as response: data = json.load(response) print( slug, data.get("active_installs"), data.get("rating"), data.get("num_ratings"), data.get("version"), )

The 12 plugins in the benchmark

The benchmark covers:

MailPoet, The Newsletter Plugin, FluentCRM, Icegram Express, Noptin, Mailster, Groundhogg, MailerPress, MC4WP, Omnisend, Brevo, and Kit.

The plugin directory slug matters. For example:

MC4WP is mailchimp-for-wp
Brevo is mailin
Kit is convertkit

Using the platform name as the slug will give you the wrong plugin or no result.

What the data actually shows

Some useful patterns:

MailPoet has the largest install base, but its rating is lower than several smaller plugins.
MailerPress has a 5.0 rating from a very small sample, so the score needs a sample-size warning.
Groundhogg has a high rating but a much smaller install base and a newer WordPress requirement.
MC4WP is a connector, not a self-hosted newsletter plugin. Its install count should not be compared directly with MailPoet’s.

That last distinction is the most important one: where subscribers are stored changes the product category.

Download the dataset

The benchmark JSON includes the 12 plugins, installs, ratings, review counts, versions, requirements, storage location, and the verification date.

https://mailers.email/data/wordpress-newsletter-plugin-benchmark-2026.json

The readable version is here:

https://mailers.email/learn/wordpress-newsletter-plugin-benchmark-2026/

Methodology matters

A benchmark is only useful if it says what it does not include. This one does not include vendor pricing, feature quality, or real delivery performance. Those need separate checks.

If you publish a plugin comparison, include: