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How much does the Yelp API cost?
You buy credit packs (or spend the 100 free signup credits). Search is 1 credit per page; details, reviews, and photos are 2 credits per completed lookup. Failed requests are not charged. Always check meta.creditsCharged. There is no required monthly subscription for pay-as-you-go packs.
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This answer comes from Yelp data API, which covers the full detail, endpoints and pricing in credits.