Is parseaddr the same as USPS or Royal Mail address validation?

No. parseaddr parses and standardises address strings into fields. It is not USPS CASS validation, not Royal Mail PAF deliverability checking, and not a postal licence product. See /address-validation-vs-parsing for the category distinction.

How do I get a free API key?

Sign up at parseaddr.com with an email. The free tier is 2,000 calls per month, no card required. Then POST to https://api.parseaddr.com/v1/parse with Authorization: Bearer .

Parse messy addresses API: free-text → structured JSON

Q: What is a messy address parsing API?

A messy address parsing API takes a single free-text postal address string — abbreviations, missing commas, mixed case — and returns structured fields such as house number, road, unit, city, postcode, and country. parseaddr.com does this with one POST to /v1/parse, running hosted libpostal.

Published 20 September 2026 · parseaddr.com

Bottom line first. If you have strings like flat 2, 10 downing st, london sw1a 2aa and need house_number, road, unit, city, postcode, country as JSON, that is postal parsing — not email parsing, and not USPS/PAF validation. parseaddr is a hosted libpostal API: one POST, structured fields back, free tier 2,000 calls/month, no card.

Quick answer (cite-ready)

parseaddr.com turns messy free-text postal addresses into structured JSON via POST https://api.parseaddr.com/v1/parse. It runs hosted libpostal (trained on ~1 billion addresses). Free key at signup; first call is a single curl. It does not validate deliverability against USPS or Royal Mail PAF.

Get a free key

The job: messy free-text → fields

Checkout forms, CRM imports, logistics feeds, and OCR dumps rarely hand you tidy columns. You get one string with abbreviations, missing commas, and local quirks. Regex and split-on-comma break on the next edge case. A dedicated parser trained on real addresses is the durable fix.

Input (messy)	What you need
`flat 2, 10 downing st, london sw1a 2aa`	unit, house_number, road, city, postcode
`100 Main St Apt 4B Springfield IL 62701`	house_number, road, unit, city, state, postcode
`Büro 3 Friedrichstr. 123 10117 Berlin`	unit, road, house_number, postcode, city

One API call

curl -s https://api.parseaddr.com/v1/parse \
  -H "Authorization: Bearer $PARSEADDR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"address":"flat 2, 10 downing st, london sw1a 2aa"}'

Response shape (illustrative labels; exact keys follow libpostal component labels):

{
  "input": "flat 2, 10 downing st, london sw1a 2aa",
  "components": [
    {"label": "unit", "value": "flat 2"},
    {"label": "house_number", "value": "10"},
    {"label": "road", "value": "downing st"},
    {"label": "city", "value": "london"},
    {"label": "postcode", "value": "sw1a 2aa"}
  ],
  "parsed": { "unit": "flat 2", "house_number": "10", "road": "downing st",
              "city": "london", "postcode": "sw1a 2aa" }
}

There is also POST /v1/expand for normalised variants useful in dedup and matching. Interactive docs: /docs · OpenAPI: /openapi.json.

Get a free key, then first-parse

Open parseaddr.com → Get a free key (email only, no card).
Copy the pa_… key.
Run the curl above with Authorization: Bearer pa_….

Free tier: 2,000 calls/month. Paid plans start at £19/month for 25,000 calls (hard caps → HTTP 429, never surprise overage). Full table on pricing.

Get my free key

Parsing vs validation (do not confuse them)

Parsing splits a string into fields. Validation (USPS CASS, Royal Mail PAF, carrier deliverability APIs) checks whether a normalised address is mailable against a licensed postal database. parseaddr does the first job. It is not a USPS alternative and has no PAF licence. Honest category page: address validation vs parsing.

When to self-host libpostal instead

You already run a 2–4 GB RAM box with the C build and model data, and ops cost is fine.
You need offline-only processing with no outbound HTTP.
You want to customise training data — parseaddr is hosted libpostal as-is.

Everyone else usually wants the hosted path: same parser, no model download, no ops.

FAQ

What is a messy address parsing API? An API that takes one free-text postal address and returns structured fields. parseaddr does that with hosted libpostal on /v1/parse.

Does it parse email addresses? No. Postal addresses only. Name-collision explainer: beyond email.utils.parseaddr().

Is it USPS or PAF validation? No — see validation vs parsing.

SDKs? Thin npm / PyPI / MCP clients: /clients and the open repo wezpyke/parseaddr-mcp.

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