Ranked on price, sign-up access, rate limits and migration effort, with the source for every number

Disclosure: I work on SightRadar, and it is first in this list. That is a vendor's ranking, so I state the criteria up front, give a source for every number, and say where each other option is the better choice.

Most "best face recognition API" lists rank on brand size, or on features copied from each vendor's docs. Neither tells you what happens when you build with one. The things that decide a project are plainer:

Can you sign up and call it today? Some APIs need an approval form before they will identify anyone.

What does a real workload cost? Per image, per transaction and per month are three different bills.

What are the default rate limits? A backfill of 200,000 photos at 5 requests a second takes eleven hours.

How much code do you write? Especially if you already have AWS Rekognition code.

Does it do recognition at all?…