NHTSA API vs TransparentCars API

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

The verdict

Choose NHTSA API if its data fits your use case better; on access and reliability it's level with TransparentCars API.
Choose TransparentCars API if you want to call it from browser JavaScript.

Side by side

	NHTSA API	TransparentCars API
What it does	NHTSA Product Information Catalog and Vehicle Listing.	Fair-price valuation and yearly road tax (IUC) for used cars in Portugal.
Provider	vpic.nhtsa.dot.gov	TransparentCars
API key	Not needed	Not needed
HTTPS	Yes	Yes
CORS (browser calls)	Unknown	Yes
Status today	Online · 704 ms	Online · 644 ms
Uptime (30 days)	Up	Up
Developer rating	Not rated yet	Not rated yet
Price	Free / free tier	Free / free tier

NHTSA docs ↗TransparentCars docs ↗

NHTSA API

NHTSA Product Information Catalog and Vehicle Listing.

Strengths

No API key needed
HTTPS

Ratings, reviews and FAQ →

TransparentCars API

Fair-price valuation and yearly road tax (IUC) for used cars in Portugal.

Open, key-free API for the Portuguese used-car market: fair-price valuation, road tax and running cost, and stock. OpenAPI 3.1, MCP server, no API key.

Strengths

No API key needed
Callable from the browser (CORS)
HTTPS

Ratings, reviews and FAQ →

How to choose between them

Prototyping or a tutorial? Pick the one that needs no API key (both qualify).
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.

NHTSA vs TransparentCars FAQ

Do NHTSA API and TransparentCars API need an API key?

Neither needs an API key; you can call both straight away.

Which can I call from the browser?

TransparentCars API supports CORS, so front-end JavaScript can call it directly. Call the other from a server.

More comparisons

NHTSA API alternatives · TransparentCars API alternatives · best Vehicle APIs