Do I need a plugin to add the review widget to WordPress?

No. The widget is plain HTML, so it goes into a Custom HTML block in the editor. No plugin to install, update or have break after a WordPress release.

Will it work on Squarespace, Wix or Shopify?

Yes. Each of them has a block for embedding HTML — Code Block on Squarespace, Embed HTML on Wix, a section or page in the Shopify theme editor. The same HTML goes into all of them.

What happens if I move to another platform later?

The block moves with you: it is HTML, not a platform-specific plugin. The reviews themselves stay on your account and can be re-embedded anywhere.

Any platform, one block of HTML

Review widget for WordPress, Squarespace, Wix and Shopify

Most review widgets ship a plugin per platform, and each plugin is a thing that can break when the platform updates. Ours does not, because there is nothing to install: you get a block of HTML with the reviews already inside it, and every builder in this list has a place to paste HTML.

Get the HTML — free → How the widget works

Why plain HTML is the point, not a shortcut

The reviews are in the page. Not fetched by a script after load — which means anything reading the HTML sees them, including the crawlers that decide whether you get star ratings in search results.
Nothing to install or update. No plugin in your admin, no version to keep compatible with the next platform release.
Nothing to break on our side. If our service went down tomorrow, the block would keep showing the reviews: they are already in your page.
It moves with you. Changing platform does not mean rebuilding the block.

Where the block goes on each platform

WordPress

Block editor: add a Custom HTML block and paste. Classic editor: the Text tab. In a theme file, paste it where the section should appear. Elementor and Divi both have an HTML widget that works the same way.

Squarespace

Add a Code Block to the page and paste. On Business plans and above this is available everywhere; on Personal, use a Markdown block with raw HTML.

Wix

Embed → Embed HTML → Code. Wix places embeds in an iframe, so give the block enough height — the reviews should not need a scrollbar.

Shopify

Theme editor: a Custom Liquid section on the product or home page. For a static page, the HTML view of the page editor.

Webflow, Tilda, Framer

All three have an embed element for raw HTML. On Tilda it is block T123; there is a Russian page about Tilda specifically (RU).

Hand-written pages

Paste it. That is the whole instruction — there is no runtime, no dependency and no build step.

What you actually get

A link and a QR code for collecting reviews. Your customer writes the review on your page — no account, no app.
Moderation. Nothing appears until you approve it, and your reply sits under the review where it does the most good.
The HTML block, with schema.org attributes on the reviews and the average rating, ready to paste wherever you want it.
An update when you need one. New reviews change the block; you paste the new version, or point at the hosted one — your call.

Star ratings in search results come from reviews collected on your own site — which is exactly what this is. How the markup works →

Questions

Do I need a plugin for WordPress?: No. A Custom HTML block is enough — there is nothing to install, update, or have break after a WordPress release.
Will it slow my page down?: There is no script to load, so there is nothing to slow down. The reviews are part of the HTML the server already sends.
Can I restyle it?: Yes — it is your markup on your page. Change the CSS as you would for anything else on the site.
What if I move from Wix to WordPress?: Paste the same block in the new place. The reviews are on your account, not wired into the platform you are leaving.