Look up without a client
A support agent can paste an address and read the answer; developers still get the API.
COMPARE · POSTCODEDOG VS ZIPCODEAPI
PostcodeDog vs ZipCodeAPI
ZipCodeAPI is an API. PostcodeDog is an API with a browser, batch and MCP.
ZipCodeAPI provides US and Canadian ZIP code APIs. PostcodeDog covers 82 countries with one lookup, batch checks, a free API and MCP.
SIDE BY SIDE
What changes with PostcodeDog
| Capability | UsPostcodeDog | ZipCodeAPI | Why it matters |
|---|---|---|---|
| Form | Lookup, batch, API and MCP | API only | Support and operations can use it without a client. |
| Access | Free, no account, no key | API key or plan | A quick check stays free. |
| Input | Paste an address, city or code; country and format detected | Endpoint | Use the customer text as-is. |
| Batch | Paste up to 50 rows, review, export CSV | One request per row | Clear a queue without a script. |
| AI agents | Built-in MCP server at /mcp | — | Connect the lookup to an agent. |
WHERE POSTCODEDOG WINS
The answer is part of the product.
No key for the basic lookup
The browser, batch page and basic API need no account or key.
Agents connect directly
The MCP server exposes lookup, search and validation to AI clients.
TRY IT
Try the difference
Paste a full address, a city or a post code. Country and format are detected.
Free. No account, no API key.THE LOOP
Paste → resolve → verify
The same three steps work whether the address is a US ZIP, a UK outcode or a Japanese 〒.
- 01
Paste what you have
A full address, a city, or just a code. The parser accepts the whole line.
- 02
Confirm the place and format
Country, region and post code format are shown together, with nearby codes for a second option.
- 03
Send it to the label
Copy the verified code or export the batch. Platform and carrier pages keep local rules in view.
About
About ZipCodeAPI
ZipCodeAPI provides US and Canadian ZIP code APIs.
It is an API for developers integrating postal data.
When PostcodeDog is the better fit
- 01You want a lookup page, not only an API.
- 02You need a batch check without a script.
- 03You want no key for basic use.
- 04You want an MCP server for AI clients.
Is ZipCodeAPI free?
ZipCodeAPI uses API keys or paid plans. PostcodeDog is free for the browser, batch, API and MCP.
Does PostcodeDog cover United States?
Yes. United States is one of 82 countries in the lookup.
Is PostcodeDog free?
Yes. Lookups, batch checks, the JSON API and the MCP server are free and need no account.
Can I use it in an AI agent?
Yes. The MCP server is at /mcp, and the JSON API is free to call.
Compare
Try PostcodeDog instead of ZipCodeAPI.
Try 90210, SW1A or 100-0001. No signup, no credit card.