Sites that publish for years end up competing with themselves: the 2019 guide
and the 2023 rewrite, the category page and the pillar post, three
near-identical round-ups. You know they are in there. What you do not know is
which one to keep, and what you would quietly lose by deleting the other.

This plugin answers both, and changes nothing until you say so.

How it works

Scan. Every post is compared against every other post that could
plausibly match it.
Compare. For each overlapping pair: which version is stronger, on what
evidence, and what only the other one contains.
Plan. A merge and redirect plan you can export and act on — by hand,
with a redirect plugin you already use, or with Pro.

What you get

Every overlapping pair, ranked. Sorted by how much they overlap, banded
near identical, strong or partial.
A canonical suggestion that shows its working. Content length,
publication date, comment activity, inbound internal links, featured image and
slug quality are scored side by side, so you can see why one version was
suggested — and disagree.
What you would lose. The question before any merge is what only the
other version has. The audit lists exactly those sections.
A redirect plan before anything is created. Source path, target path,
status code.
CSV export. The duplicate report and the redirect plan, in a shape other
redirect plugins can import.

Similarity detection that assumes spaces between words fails badly on
Japanese, Chinese and Korean. This plugin detects the script and switches from
word shingles to character shingles, so CJK content is compared properly
instead of producing noise.

What it will not do

Read-only. It never merges, deletes, rewrites, trashes or redirects
anything. Every destructive step stays with you.
Nothing leaves your server. No external service is contacted, no
analytics, no telemetry.
No account, no API key. Install it and use it.
Tidy. Scan data lives in three tables of its own, which are removed when
you uninstall.

This plugin, and the Pro plugin

Free is a complete job: find the overlap, understand it, decide, export the
plan. It is not a trial — nothing expires and no feature stops working. A
separate Pro plugin, distributed outside WordPress.org and not bundled here,
carries the plan out.

This plugin, free, does all of the analysis:

Finds every overlapping pair and ranks them
Shows why one version is suggested, signal by signal
Shows what only the other version contains
Previews the merge and the redirect
Exports the whole plan as CSV

Pro carries the plan out, inside WordPress:

Performs the merge
Creates the 301 redirects
Rewrites internal links pointing at the retired post
Revision backup, rollback and conflict detection

Matches are banded — near identical, strong overlap, partial overlap —
because a bare percentage is harder to act on than a category.

Try it without installing

A WordPress Playground blueprint ships with this plugin. When the directory
offers a Live Preview for it, that preview boots a temporary WordPress in your
browser, seeded with posts that overlap on purpose, and opens straight on the
results. Nothing is installed on your own site.

Full documentation, worked examples and the Free/Pro comparison:
https://hublo-wp.com/free-plugins/duplicate-content-auditor/

External services

This plugin does not contact any external service on its own. Nothing is sent
from your site in the background.

The “Upgrade to Pro” button is an ordinary link. If you click it, your
browser opens https://hublo-wp.com/buy/duplicate-content-auditor, operated by
HUBLO. While the Pro edition is on sale, that address takes you to Stripe’s
hosted checkout, where Stripe takes the payment; this plugin never sees or
handles card details. The link carries no query
string: your site address, your email address, your installation identifier
and your scan results are never appended to it and never leave your site.
Nothing happens until you click.

The Pro edition is a separate plugin distributed outside WordPress.org. This
plugin never downloads it, never installs it and never updates it. It fetches
no executable code from anywhere. After purchase you download the Pro ZIP in
your browser and install it yourself via Plugins > Add New > Upload Plugin.

Purchase service: https://hublo-wp.com/buy/duplicate-content-auditor – operated by HUBLO
Payment processing: Stripe – https://stripe.com/privacy
Terms: https://hublo-wp.com/terms/
Privacy: https://hublo-wp.com/hublo-privacy-policy/
Refunds: https://hublo-wp.com/refund-policy/

HUBLO Duplicate Content Auditor