Once a query is submitted, the search engine has two jobs: interpret what the shopper meant, and find products that match. Most zero-result searches fail at interpretation, not matching.
The first interpretation problem is character errors. Shoppers type imperfectly, producing queries like 'snikers,' 'iphon case,' 'waterpoof jacket and basic search engines treat these as completely different strings from the products they're trying to find. The fix is a search engine that corrects these errors before attempting to match. Shopify includes basic error correction that covers one or two character changes depending on word length, but only across certain fields and only for straightforward substitutions. Phonetic errors and alternate spellings fall outside it.
The second interpretation problem is vocabulary. A shopper searching "couch" and a catalog listing "sofa" contain no matching characters, so a keyword matching engine sees two unrelated strings. Closing this gap requires explicit terminology mapping: a structured list that tells the engine which words mean the same thing in the context of this catalog. Start by pulling your top zero-results queries from search analytics. Synonym gaps are usually obvious from that list.
The first improvements after enabling synonyms show up in your zero-results report almost immediately. Each entry you add closes a recurring gap that would otherwise cost a sale every time that query is entered. The payoff compounds: a synonym set up once fixes every future search that hits the same gap.
Merchants typically see the most immediate impact from addressing character errors and vocabulary gaps first. These cover the highest volume of failing queries and require the least configuration effort. Limited100 cut their bounce rate from
28% to 18% and boosted engagement by 55% after optimising their Shopify search experience.