Addrex Address Validation API vs USPS Addresses API

Addrex Address Validation API validates and standardizes U.S. addresses, returning match codes, confidence scores, coordinates, and standardized fields. It supports API requests as well as spreadsheet cleanup: users can upload CSV or Excel files, process detected address columns, and download cleaned data with output fields appended. Cleanup can expand abbreviations, correct typos, parse grid-style inputs, and append ZIP+4 when a match is available. The API accepts a one-line address or structured address fields and returns JSON with validation status, confidence, standardized results, and changes. Free Beta allows 10,000 validation rows per day, requires email verification, and does not include autocomplete. The listed Free Beta plan has 10,000 address lookups per month; paid plans start at $39 a month. Autocomplete suggestions and details are restricted to paid plans. Real-time API address data is not retained beyond the request, while batch files default to seven days of retention and can be deleted sooner. Addrex does not claim USPS DPV or CASS certification.

USPS Addresses API has no write-up on Specifiction yet; its figures are above.