
USZipLookup
ZipCheckup
ZIP Code API
Smarty
Geoco.io
AZIPCODE
PostalCodes.app
Use our free ZIP Code Analysis Tool to find city, state, county, population, and timezone details for any U.S. ZIP code. Fast, accurate, and privacy-safe lookup.

Ideal postcodes
Fetchify
Loqate
Data8 UK
Data8 UK PredictiveAddress
Email Verification API
Google Maps API
Fast UK address, email & phone validation APIs for developers. Official Royal Mail PAF data. Pay as you go, 100 free lookups.

Which is more popular?
Website, pricing, platforms and company facts side by side.
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| Website | uszipcodes.org | postio.co.uk |
| Pricing | ||
| Platforms | ||
| Company | Startup from India · 2025 | Startup from the United Kingdom · 1 - 9 employees |
| Listed in |
In their own words, as submitted to SaaSHub.


ZIP Code Analysis Tool is a web-based application that allows users to search any US ZIP code and instantly view detailed location-based data. The tool provides accurate information including city, state, county, latitude, longitude, and population statistics. It is designed for researchers,...
Postio (postio.co.uk) is a developer-focused data validation platform providing real-time UK address lookup, email verification, and phone validation via plain REST APIs and drop-in SDKs. As an official Royal Mail PAF Solutions Provider, Postio synchronises 30M+ UK addresses daily for accurate...
What each product offers, as listed by its team.


An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
No analysis of Postio.co.uk yet.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing usZIPCodes.org and Postio.co.uk.
usZIPCodes.org's answer
Their ability to translate simple postal codes into sophisticated geographic insights for a wide range of business and research applications beyond their original mail delivery purpose.
Postio.co.uk's answer:
Postio charges only when a lookup returns a result — searching is free. Address, email and phone validation sit behind one API with a single JSON response envelope, so you integrate once rather than stitching three vendors together. Address data comes from Royal Mail's Postcode Address File under a direct licence, not scraped or resold sources. There are no tiers, contracts or minimum spend, and the first 100 lookups need no card.
usZIPCodes.org's answer
The "story" behind the concept of a "ZIP Code analysis tool" is not about a single specific software product, but rather the evolution of the ZIP Code itself from a simple postal sorting mechanism into a powerful, multifaceted geographic data analysis unit used across many industries.
Postio.co.uk's answer:
Postio is a trading name of Onno Group Limited, registered in England & Wales (company no. 08622799). It was built to make Royal Mail PAF-accurate UK validation available on straightforward pay-as-you-go pricing, rather than the contracts and minimum commitments that have been standard in this market. Address, email and phone validation were brought together behind one consistent API so a team can solve all three at once.
Postio.co.uk's answer:
A REST API served from edge locations, with official SDKs for JavaScript/Node, Python, Go, PHP, Ruby and .NET, all open source on GitHub. The API is documented by a public OpenAPI specification.
Postio.co.uk's answer:
Pricing is published and pay-as-you-go: 2.2p per address, 1p per email, 1p per phone, billed only on a result. No sales call, no annual contract, no minimum commitment. You can be live in a few minutes with 100 free lookups and no card, and the same API covers all three validation types. For UK addresses specifically, the data is licensed directly from Royal Mail rather than obtained second-hand — which matters after the 2025 High Court ruling on database rights in this market.
Postio.co.uk's answer:
Developers and technical teams building UK-facing forms — ecommerce checkouts, signup flows, CRM and logistics systems. Typically small to mid-sized product teams, agencies building for UK clients, and software vendors embedding address lookup in their own product. It suits anyone who wants a UK-accurate API without an enterprise procurement process.
Postio.co.uk's answer:
Serving a huge range of customers across the world looking for a blazing fast UK Address AIP product. From bootsrapped entrepreuners to FTSE 250 companies. We serve them all.
Share your experience with using usZIPCodes.org and Postio.co.uk. For example, how are they different and which one is better?
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