RankVN SEO has strong Vietnamese-language support (accent-aware processing, Vietnamese keyword analysis and a bundled Vietnamese translation).

The Free build runs on your server — no remote licensing calls and no telemetry without your consent.

What you get in Free

Meta title & description — customize Google snippets for posts, pages and the homepage.
Open Graph & Twitter Cards — richer social previews with safe image handling.
Unified Schema Graph — one connected JSON-LD block (WebSite, WebPage, Article, Author, BreadcrumbList) plus types you add in the editor (FAQ, HowTo, Product, LocalBusiness, Event and more).
XML & HTML sitemaps — XML and customizable HTML sitemaps; the WordPress sitemap is off while RankVN’s XML sitemaps are on.
Robots.txt & robots meta — virtual robots.txt; noindex, nofollow and noarchive per post or page; noindex per category or tag. Sitemaps, llms.txt and IndexNow skip content that is not public.
Canonical URLs — archives and page 2 and later point to their own address; search and 404 pages print none. A custom category or tag canonical applies to all its pages; on the posts page, to page 1 only.
Table of contents — heading-based TOC via shortcode.
Reader rating widget — visitor ratings with AggregateRating schema (no IP storage).
Image SEO (Alt + Optimize) — suggest and save alt text, WebP/AVIF variants and Media Health reports.
Shared images — the editor image panel can copy an image for the edited position, asking first if another post uses it or you cannot edit it; the server never edits the post.
llms.txt — a plain-text map of your site for AI crawlers (optional).
Features toggles — turn modules on/off; their settings tabs follow.

External Services

This plugin can connect to the following third-party services. All of them are OPT-IN — nothing is contacted until you explicitly enable/configure it in the plugin settings.

IndexNow

Used to notify search engines (Bing, Yandex, and others) that a URL was added or updated, so they recrawl it faster. When enabled, on publish/update the plugin sends the changed URL and your site’s IndexNow key to https://api.indexnow.org. No visitor or personal data is sent.
Protocol/terms: https://www.indexnow.org/ · Bing privacy: https://privacy.microsoft.com/privacystatement

Google Tag Manager (GTM)

Optional. Loaded only if you enter a GTM container ID. The plugin outputs Google’s GTM loader (https://www.googletagmanager.com) so tags you configure in your own GTM account run on your site. Data sent is defined by your GTM configuration.
Terms: https://marketingplatform.google.com/about/analytics/tag-manager/use-policy/ · Privacy: https://policies.google.com/privacy

Google Analytics 4 (GA4)

Optional. Loaded only if you enter a GA4 Measurement ID. The plugin outputs Google’s gtag.js loader (https://www.googletagmanager.com/gtag/js) to send visitor analytics to your GA4 property.
Terms: https://marketingplatform.google.com/about/analytics/terms/us/ · Privacy: https://policies.google.com/privacy

Microsoft Clarity

Optional. Loaded only if you enter a Clarity project ID. The plugin outputs the Clarity loader (https://www.clarity.ms) to send session/heatmap analytics to your Clarity project.
Terms: https://clarity.microsoft.com/terms · Privacy: https://privacy.microsoft.com/privacystatement

Note: the SEO analysis feature may fetch pages on your own website (same domain) to read their rendered HTML; no data is sent to any third party.

The Free version does not include any licensing or AI client and never contacts a RankVN server; all AI features are part of RankVN SEO Pro only.

Privacy

RankVN SEO Free does not send your site data externally by default.
* IndexNow: only active if you enter an IndexNow key; sends the submitted public URL plus the key (see External services).
* Google Tag Manager / Google Analytics 4 / Microsoft Clarity: tracking snippets are only rendered if you explicitly enable them and enter the corresponding ID; data is then collected by those third parties from visitors’ browsers.
* Reader Ratings: stores total vote counts and rating averages in local WordPress post metadata only. No visitor IP addresses, browser cookies, or personal tracking tokens are collected.
* The Free version does not contact a RankVN server; licensing and AI features are Pro-only.