Asking your happy customers to write testimonials for your product/service and displaying them on your website is a great way to promote your business and boost your sales. I have tested more than 10 free testimonial plugins from WordPress.org plugin repository, and now present you my top 3 list.
Strong Testimonials

Strong Testimonials is by far the most popular free WordPress testimonial plugin on WordPress plugin repository. It has more than 60,000 active installation and received 5 star ratings. The first version was released on early 2016 and has been well maintained since then.
Main Features:
- A front-end form: an input form to let your customers filling the testimonials by themselves
- Star ratings & Custom fields & Captcha: add star ratings and your own customised fields to the testimonial form. It also supports third-party captcha plugins for anti-spam.
- Categories: by using categories, you could ask your customers to write testimonials for multiple products or services
- Versatile display options: display testimonials in carousels, sliders and lists
Site Reviews

Site Reviews is a great plugin that allows your visitors to submit star ratings, reviews and comments to your posts. The plugin uses Shortcode to display a submit form which can be added to your WordPress theme file and assign the submitted reviews to a WordPress post.
Main Features
- Submit star rating and review
- Assign reviews to WordPress posts
- Support Google reCaptcha V3
- Shortcodes to display submit forms and all reviews
- Integration with Akismet
Testimonial Rotator

If you are looking for displaying testimonials in a carousel or rotator, Testimonial Rotator is a good choice. The plugin has been released for more than 4 years and has been actively maintained. It has more than 50,000 active installation and is awarded a 4.5 star rating by reviewers.
The plugin author also created a nice YouTube video which can help you quickly master the plugin: Testimonial Rotator Overview YouTube Video.
Though the plugin does not have a built-in front-end input form, you can use the premium plugin Gravity Forms to create a testimonial submission form.
Main Features
- Add testimonials to multiple rotators / carousels
- Make custom rotator templates
- Create testimonial submission form with Gravity Forms