US Autocomplete API vs US Street Address API

Two free Data Validation APIs compared on access, reliability and developer ratings, using data from our daily health checks.

The verdict

Choose US Autocomplete API if its data fits your use case better; on access and reliability it's level with US Street Address API.
Choose US Street Address API if you want faster responses.

	US Autocomplete API	US Street Address API
What it does	Enter address data quickly with real-time address suggestions.	Validate and append data for any US postal address.
Provider	Smarty	Smarty
API key	Required	Required
HTTPS	Yes	Yes
CORS (browser calls)	Yes	Yes
Status today	Online · 976 ms	Online · 559 ms
Uptime (30 days)	Up	Up
Developer rating	Not rated yet	Not rated yet
Price	Free / free tier	Free / free tier

Enter address data quickly with real-time address suggestions.

Address autocomplete | Use our Autocomplete API to suggest valid addresses in real time as users type. Uses a simple HTTP endpoint.

Strengths

Validate and append data for any US postal address.

Complete documentation of Smarty's US address validation API including URL composition, input and output fields, and status codes.

Strengths

Prototyping or a tutorial? Pick the one that needs no API key (neither does, so compare their free tiers).
Calling from a web page? You need CORS. Otherwise route requests through your own server or a serverless function.
Going to production? Favour HTTPS, a strong uptime record and a provider with clear rate limits and terms. Check each API's docs before you commit.
Still unsure? Both are free to try: send one request to each and compare the data you get back.

Both require authentication (apiKey and apiKey).