GridVigil API vs WattFigure API

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

The verdict

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

	GridVigil API	WattFigure API
What it does	Pressure scores, demand, generation mix and alerts for the 10 major U.S. power grids.	US electricity rates by state, with appliance and EV charging running costs.
Provider	GridVigil	WattFigure API
API key	Not needed	Not needed
HTTPS	Yes	Yes
CORS (browser calls)	Yes	Yes
Status today	Online · 1588 ms	Online · 712 ms
Uptime (30 days)	Up	Up
Developer rating	Not rated yet	Not rated yet
Price	Free / free tier	Free / free tier

Pressure scores, demand, generation mix and alerts for the 10 major U.S. power grids.

GridVigil's free Developer API: one normalized JSON schema across every grid it tracks, with example requests and responses.

Strengths

US electricity rates by state, with appliance and EV charging running costs.

Strengths

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.

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