Methodology
As of October 24, 2026: 14 categories and 279 models. Japanese reference prices cover 276 models; 176 are the lowest online-shop prices on Kakaku.com (excluding shipping), and the rest are manufacturer list prices or official-store and retail prices. 23 models also have the manufacturer list price recorded. Chinese e-commerce prices are not yet collected, so most models have no "worth it" verdict on the Chinese site yet. 116 ratings (from third parties such as Kakaku.com and @cosme). 26 stores, 23 of which have been checked against official websites. Kakaku.com prices, ratings and exchange rates are collected automatically every Monday; prices that change by more than 30%, or whose lowest online price is more than 10% above the manufacturer list price, are flagged "needs review" (currently 7).
Data sources
The table below is generated from the sources actually recorded in the data (for each kind of data, the most-cited sources, with the number of models in brackets). Every product page lists the source link and date for each figure.
How often data is updated
Current data: Japan prices last collected 2026-10-24; Japan prices cover 99% of models and third-party ratings 41%; 7 prices are under review. See data status.
Planned schedule (the dates on each page are what count):
- Prices and exchange rates: every 2 weeks per category, weekly for popular models
- Ratings and new models: monthly
- Stores and rules: checked quarterly, and immediately when rules change
Quality rules
- Nothing made up: missing fields stay empty and pages show "TBD"
- A price change of more than 30% at once does not overwrite the old value; it is marked "under review"
- Models are never deleted: models we can no longer find are marked "may be discontinued"
- Every update is validated automatically: JSON format, required fields, model count not decreasing, prices within reasonable ranges
- Every update is a Git commit and is recorded in the changelog, so mistakes can be rolled back
- Copyright: we store only facts such as prices and ratings plus source links; pros and cons are our own summaries, and review text is not stored
Japan price and tax-free price
Tax-free price = price incl. tax ÷ (1 + consumption tax rate). The rate is usually 10%, and 8% for food and drinks. The price type is labeled on each page: lowest online price (shipping not included), manufacturer list price or store price. When the lowest online price is more than 10% above the list price, it is marked "under review". The Chinese version of the site also compares with prices in mainland China; the English version does not.
How compatibility is decided
Rules are kept in a separate rule set and matched check by check; the first matching rule gives the result. The worst of the usage checks decides the overall verdict (works as is / needs an accessory / will not work). Each destination's standard voltage, frequency and outlet types come from published national standards (IEC World Plugs).
- Voltage: 10 rules
- Plug: 5 rules
- Frequency: 6 rules
- Region lock / language: 4 rules
- Customs on arrival: 11 rules
- Flight rules: 16 rules
Destinations: Mainland China (220V/50Hz), Hong Kong (220V/50Hz), Macao (220V/50Hz), Taiwan (110V/60Hz), Singapore (230V/50Hz), South Korea (220V/60Hz), United States (120V/60Hz), Japan (100V/50/60Hz), Thailand (220V/50Hz), Malaysia (240V/50Hz), Philippines (220V/60Hz), Vietnam (220V/50Hz), Indonesia (230V/50Hz), India (230V/50Hz), Australia (230V/50Hz), New Zealand (230V/50Hz), Canada (120V/60Hz), United Kingdom (230V/50Hz), Germany (230V/50Hz), France (230V/50Hz), Italy (230V/50Hz), Spain (230V/50Hz).
220V models in 230–240V countries: each model's voltage range follows the manufacturer's website or manual (a model rated 220–230V is recorded as 220–230V). If the range covers the local voltage, voltage counts as "works as is". If a model is rated 220V only and the manufacturer says nothing about 230–240V, it goes in the "needs an accessory" group with the note "check the manual before long-term use". If the manufacturer limits a model to its rated voltage or to mainland China, it is rated "will not work". Manufacturer statements and sources are in Will Japanese appliances work in 110V and 220V countries?
Tax refund calculation
Consumption tax 10%. Incl. → excl. tax is rounded to the nearest yen; excl. → incl. is rounded down. The tax-free rule is chosen by purchase date: Old rule: tax exempted at the store (minimum JP¥5,000); New rule: pay tax first, refund on departure (refund system) (minimum JP¥5,000).
Product images
Product images come first from the official Rakuten Ichiba API (shown under Rakuten's terms and linked back to the item page). For models not on Rakuten we use the share image (og:image) published on the manufacturer's product page, referenced directly from the official site with the source labeled and a link to it; copyright belongs to the manufacturer, and we remove images on request. Other models use a text cover.
Translation
The English pages are translated with AI from the Chinese original, which is authoritative. Translations may not add facts, figures or claims that are not in the original. Model numbers, prices, spec values and source links are not translated; source names are shown as recorded.
Independence
Rankings are based only on third-party ratings and prices; we do not accept paid placement. Ads on the page are unrelated to the content.
Product images from Rakuten Ichiba and links to Rakuten are Rakuten affiliate links: if you buy through them we may earn a small commission at no extra cost to you. Commissions do not affect rankings or verdicts, and the ranking code does not read any commission information.