Every "best text-to-speech API" list I have read is ranked. Number one, number two, number three, with a verdict at the bottom.
That shape cannot express the actual decision, and I want to show you why with something you can run.
The problem is that the three things that decide a TTS vendor are measured in units that do not convert into each other. Price is dollars per million characters. Transport is a shape — held-open socket, chunked body, finished file. Compliance is a document that either exists or does not. There is no exchange rate between them, so there is no ordering. A ranked list has to pick one axis and pretend the others are tiebreakers.
They are not tiebreakers. They are filters, and filters compose by intersection.
The three sets
