Chempirical API vs MathJS API

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

The verdict

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

Side by side

	Chempirical API	MathJS API
What it does	Chemical compounds with physical data, reactions and substructure search.	Evaluate math expressions via GET or POST as JSON.
Provider	Chempirical	math.js web service
API key	Not needed	Not needed
HTTPS	Yes	Yes
CORS (browser calls)	Yes	Yes
Status today	Online · 533 ms	Online · 934 ms
Uptime (30 days)	Up	Up
Developer rating	Not rated yet	Not rated yet
Price	Free / free tier	Free / free tier

Chempirical docs ↗MathJS docs ↗

Chempirical API

Chemical compounds with physical data, reactions and substructure search.

Free read-only JSON API for 48,000 compounds, reactions, Antoine constants and azeotropes: search, identifiers, physical data, structure images and reaction scaling.

Strengths

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

Ratings, reviews and FAQ →

MathJS API

Evaluate math expressions via GET or POST as JSON.

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.

Chempirical vs MathJS FAQ

Do Chempirical API and MathJS API need an API key?

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

More comparisons

Chempirical API alternatives · MathJS API alternatives · best Science & Math APIs