Full disclosure before anything else: I build one of these. Queryra is mine. That is exactly why I went and read what the other eight actually say about themselves, rather than what their names imply.
I did not run a benchmark this time. I read plugin pages. All of them, line by line, the way nobody does before installing something. It took an afternoon and it was more revealing than any test I have run, because almost every meaningful difference between these plugins is sitting in plain sight, in their own words, one scroll below the headline.
If you want the verdict on which plugins genuinely use vector embeddings, I wrote that up separately in Which WordPress AI Search Plugins Actually Use Semantic Search?. That post answers which. This one answers who pays for it, and how you check any of it yourself.
The thing nobody checks
"AI search" is not a protected term. A plugin can carry *AI*, *semantic* or *vector* in its name while running the same word-counting algorithm that WordPress search has used for twenty years.
I am not accusing anyone of lying. The opposite, actually: the plugins below are honest in their own documentation. The gap is between what the name promises and what the description says, and the description is usually two paragraphs down.
So this post has one rule. Every claim below is quoted from the plugin's own page and you can check it yourself in about thirty seconds. No insider knowledge, no test rig, no trust required.
Group 1: the ones that never claimed AI
Start here, because this is the control group and it makes the rest legible.
FiboSearch describes an *"Ultra-fast search engine based on the inverted index"* and *"Fuzzy search, works even with minor typos"*. Nowhere on its page does the word *semantic* or *embedding* appear. It is a keyword search plugin and it says so.
Relevanssi goes further and publishes its actual method: *"Fuzzy matching: match partial words, if complete words don't match"* and *"tf * idf weighing"*. That is term frequency against inverse document frequency, a technique from the 1970s that still works extremely well. Relevanssi tells you this on the plugin page. Remember that sentence, it comes back later and it is the most useful thing in this post.
SearchWP offers a *"Customizable Algorithm"* and a *"Smart Search Algorithm"* that *"auto-improve[s] based on user behavior"*. No AI, no vectors, no embeddings claimed anywhere.
These three are the honest baseline. If your shoppers search the way people searched in 2015, typing one or two nouns, these plugins are genuinely good and you can stop reading. The reason to look further is if your shoppers have started typing sentences, which is a separate question I will not pretend to settle here.
Group 2: "semantic" in the name is not a method
Softlinkster Semantic Search is the clearest example I found, and I want to be fair to it: they do not hide anything. The plugin is called *Semantic Search*. Its own feature list says *"BM25 Ranking, Industry-standard text relevance scoring with TF-IDF weighting"*.
BM25 and TF-IDF are keyword ranking. Good keyword ranking, genuinely, and the plugin is free, self-hosted, needs no external service, and handles SKUs, attributes and Woo variations. If that is what you want, it is a reasonable pick.
But put it next to Relevanssi for a second:
