Is there a free tier or trial?

No. Creating an account, generating keys and reading the documentation are free, and the homepage shows example responses, but live assessments need a paid plan. New accounts start with zero credits.

Do unused credits expire?

Not while you subscribe. Monthly credits and pack credits roll over. If you cancel, remaining credits are kept and restored if you resubscribe.

Yes. Upgrades and downgrades take effect at the next renewal. Extra packs are available immediately on any active plan.

What payment methods are accepted?

Card payments through Stripe. Invoicing for larger volumes is available on request.

Is pricing the same for every language?

Yes. A Mandarin recording and an English recording of the same length cost the same number of credits, and every plan includes all seven languages.

Pricing: Pronunciation Assessment API from $10/month

Plans

Starter

^$10/ month

2,500 credits every month

All 7 languages
Unused credits roll over
Add extra credits anytime
API keys, playground & usage

Choose Starter

Builder

Scale

^$150/ month

50,000 credits every month

All 7 languages
Unused credits roll over
20% off extra credit packs
API keys, playground & usage

Choose Scale

Credits arrive after each successful payment and roll over while you subscribe. Plan changes apply at renewal. Cancel anytime; access continues to the end of the paid period and remaining credits are kept if you resubscribe.

What a credit buys

Recording length	Credits	Starter	Builder	Scale
Up to 15 seconds	1	$0.0040	$0.0033	$0.0030
15 to 30 seconds	2	$0.0080	$0.0066	$0.0060
Failed or unassessable	0	free	free	free

Prices per recording are the plan price divided by included credits. A request that fails, times out, or returns assessable: false (silence, wrong sentence, unreadable audio) is not charged. A retried request with the same Idempotency-Key returns the original result and is not charged again.

Extra credit packs

Pack	Credits	List price	On Builder (10% off)	On Scale (20% off)
Starter pack	2,500	$10	$9	$8
Builder pack	10,000	$40	$36	$32
Scale pack	25,000	$100	$90	$80

Packs are one-time purchases available to any active subscription and never expire while you subscribe. They are the right tool for a launch spike or a school term; if you need packs every month, the next plan up is cheaper.

Three examples

A prototype with 50 testers doing ten sentences a day: about 15,000 recordings a month → Builder, $50.
A classroom product with 2,000 students doing one five-sentence exercise a day on school days: about 200,000 recordings a month → Scale ($150, 50,000 credits) plus six Scale packs at $80 → $630, or $0.0032 per recording.
A flashcard app where 5% of 10,000 monthly users try the speaking feature five times: 2,500 recordings → Starter, $10.

Limits on every plan

Up to 30 seconds and 10 MB of audio per request; up to 40 words (100 Mandarin characters) of reference text.
Two concurrent requests per account. Queue on your side if you burst higher; overloaded requests return a retryable error and are not charged.
Scripted speech only: the learner reads the text you send.

Need higher concurrency or an invoice? Email us. For how these prices compare with SpeechSuper, Speechace and Azure, see the pricing comparison.

Simple monthly plans. Pay per assessment.