How we select products and write guides

JPSaver organizes public Amazon Japan product information into buying guides for people shopping in Japan. We do not conduct hands-on performance tests.

Product selection and ordering

New popular-product candidates require a listed rating of at least 4.0 and at least 50 ratings. A rating count is not the number of individual review texts we have analyzed. Focused comparisons are ordered by listed price, not tested performance. Different departments are directories, not head-to-head rankings.

Displayed ratings

The rating is Amazon’s listed score. Popularity is calculated from the logarithm of the listed rating count, capped at five points. These are marketplace indicators, not independent test scores. Legacy ratings obtained by the old parser are hidden until rechecked. We do not turn price bands or discounts into a value-for-money score.

Sources and limitations

New articles use AI to organize collected product specifications and any manufacturer documentation we can match to the model. They include source references and collection dates. Search-result snippets are not used as evidence. Missing specifications, language support, warranty terms and compatibility remain unverified. Older articles are being updated with source references.

Automated checks look for missing content, unknown citations and explicit claims of hands-on testing. These checks cannot prove every claim. Confirm the exact model and requirements with the manufacturer before buying.

Affiliate links and prices

We participate in the Amazon Associates program and may receive a commission when you buy through our links. Price, availability, seller and warranty conditions can change. Confirm the current details on Amazon. Our guides do not claim to be a complete market survey.