Axure
Balsamiq
Invision
Zeplin
Moqups
Proto.io
ProtoPie
Flinto
PostalDataPI
Smarty
Melissa Data Quality
PostalDataPI is a global postal code validation and enrichment API covering 240+ countries and territories. One API, one key, one flat rate โ $0.000028 per query with no tiers or subscriptions.
What you get back: Up to 18 metadata fields per postal code โ city, state/region, coordinates, timezone, three levels of administrative hierarchy, elevation, and more. Sub-5ms cached responses.
Works everywhere: US ZIP codes, UK postcodes, German PLZ, Japanese postal codes, Canadian FSAs, and 230+ more. Format normalization handles case, spacing, and hyphen variations automatically.
Get started in 60 seconds: 1,000 free queries on signup, no credit card required. SDKs for Python and Node.js. MCP server for AI agents (Claude, Cursor, etc.).
Built for developers: REST API, consistent JSON responses across all countries, OpenAPI spec, llms.txt for AI agent discovery.
Axure
PostalDataPIBalsamiq - Balsamiq. Rapid, effective and fun wireframing software.
Smarty - Smarty provides address validation, autocomplete, geocoding and reverse geocoding services covering addresses in over 240+ countries.
Invision - Prototyping and collaboration for design teams
Melissa Data Quality - Melissa helps companies to harness Big Data, legacy data, and people data (names, addresses, phone numbers, and emails).
Zeplin - Collaboration app for UI designers & frontend developers
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project