Check the destination before the label
A US ZIP is one of 82 formats. PostcodeDog handles the US, UK, Japan, Germany, France and more without changing tools, and each country page states what the data can confirm.
COMPARE · POSTCODEDOG VS USPS
PostcodeDog vs USPS ZIP Code Lookup
One lookup for every destination, not just the United States.
USPS ZIP Code Lookup is the official place to check a US ZIP Code. PostcodeDog is built for the moment before an international label: the destination is outside the US, the format is different, and the team needs an answer in one box.
SIDE BY SIDE
What changes with PostcodeDog
| Capability | UsPostcodeDog | USPS ZIP Code Lookup | Why it matters |
|---|---|---|---|
| Coverage | 82 countries in one lookup | United States only | Cross-border orders rarely stop at one country. |
| Input | Paste a full address, city or code; country and format detected | Find by US address, city/state or ZIP | Support can use exactly what the customer sent. |
| Formats | US ZIP, UK outcode, Japan 7-digit, Germany 5-digit and more | US ZIP Codes | The destination sets the format. |
| Batch | Paste up to 50 rows, review, export CSV | One lookup at a time | Clear a label queue in one pass. |
| Developer access | Free JSON API and MCP server, no key | USPS developer APIs require separate registration | Checkout and agents can call the same lookup. |
| Workflow | Platform and carrier pages for orders, labels and warehouses | US mailing rules | The answer sits next to the task. |
WHERE POSTCODEDOG WINS
One tool from the order page to the international label.
Paste, do not retype
Addresses from marketplaces arrive as one messy line. Paste the whole thing; the parser finds the country, city and code instead of asking the team to split it by hand.
Give the whole team one tool
Support uses the box, operations uses the batch page, developers use the API and agents use MCP. One lookup, one set of answers.
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
From order page to label
Copy the address once, verify the destination and keep the format rules in view while the label is filled.
- 01
Paste the order address
A US address, a UK outcode or a Japanese 〒 — the parser accepts the whole line.
- 02
Confirm the destination
Check the country, region and post code before printing. Nearby codes help when the address is incomplete.
- 03
Print with the right format
The carrier pages keep US ZIP, UK outcode and Japan 7-digit rules next to the lookup.
About
About USPS ZIP Code Lookup
USPS ZIP Code Lookup is the United States Postal Service’s free tool for finding ZIP Codes by address, city and state, or for listing cities by ZIP Code. It is the reference for US mailing addresses.
PostcodeDog covers the US alongside 81 other countries, so the same lookup works when the next order ships to Japan, Germany or the UK. The US is one destination in a global lookup, not the whole product.
When PostcodeDog is the better fit
- 01Your destinations include the US and at least one other country.
- 02You want a free batch check before printing labels.
- 03You need an API or MCP server without a USPS developer onboarding.
- 04Your support team works in a language other than English.
How does PostcodeDog handle US addresses?
The US is one of 82 countries. Paste a 5-digit ZIP, a city or a full address and the lookup returns the place, region and format. USPS remains the official source for US mailing rules, and PostcodeDog is a separate tool.
Can PostcodeDog look up US ZIP Codes?
Yes. The US is one of the countries in the dataset, and the lookup accepts 5-digit ZIPs, cities and full addresses.
Can I check a batch of addresses?
Yes. Paste up to 50 rows into the batch page, review the statuses and export a CSV.
Can I use it in an AI agent?
Yes. The MCP server is at /mcp, and the JSON API is free to call.
Compare
Check the destination, not just the ZIP.
Try 90210, SW1A or 100-0001 in the same box. No signup needed.