Smarty
Zipcodestack
PostalDataPI
Geoco.io
Melissa Data Quality
Loqate
usZIPCodes.org
REST API for US ZIP, ZIP+4, and Canadian postal codes. Single unified endpoint covers address validation and standardization, radius search (centroid haversine and true spatial polygon intersection), point-to-point distance, autocomplete/typeah

LeetCode
The bug you can't spot today ships tomorrow. Train before the incident: one realistic AI pull request a day, graded against a canonical review. Free, no signup.
Which is more popular?
Website, pricing, platforms and company facts side by side.
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ZIP
ZIP Code API
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| Website | zip-codes.com | diffdojo.com |
| Company | Startup from the United States · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.

API for US ZIP, ZIP+4, and Canadian postal code data. One unified endpoint set covers North America — no separate APIs by country or data type. What it does Address validation and standardization — production-grade parser with ZIP+4 append, refreshed monthly Radius search — centroid haversine and...
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Practice and level up your development skills and prepare for technical interviews.
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Free Zip Code API - Free Postal Code Validation | Zipcodestack
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The most affordable postal code API. 240+ countries, sub-5 ms responses. Simple, elegant, transparent.
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ridiculously cheap bulk geocoding turn US street addresses into map coordinates and map coordinates into street addresses using our straightforward REST API
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