This comparison is published by TonePerfect. Competitor facts were checked on 10 September 2026 against the vendor's public pages linked below; prices and features change, so confirm on their site before you decide. Where the other product is the better choice, we say so.
Where ELSA is the better choice
- English depth. ELSA's engine is trained on a very large base of non-native English speakers and reports pronunciation, word stress, intonation and fluency for both scripted and unscripted input, with IELTS and TOEFL score prediction. If your product is English-only and exam-oriented, that is hard to match.
- Unscripted speech. ELSA scores free speech; TonePerfect requires the reference sentence.
- Brand recognition with learners. ELSA's consumer app is widely known; "powered by ELSA" carries weight in English-learning markets.
Where TonePerfect is the better choice
- Languages other than English. ELSA's API is English-only. TonePerfect scores Mandarin, English, French, Spanish, German, Italian and Portuguese with one response shape.
- Mandarin tones. Initial, final and tone per syllable with expected vs estimated heard values and a decision.
- Published, self-serve pricing. ELSA's API pricing is on request. TonePerfect's plans are public and start at $10/month; you can create a key without talking to sales.
- No audio retention. Recordings are deleted after scoring and never used for training.
Side by side
| Feature | ELSA API | TonePerfect |
|---|---|---|
| Languages | English | Mandarin Chinese (zh-CN), English (en-US), French (fr-FR), Spanish (es-419), German (de-DE), Italian (it-IT), Portuguese (pt-BR) |
| Scripted assessment | Yes — word, sentence | Yes — word, sentence, sound |
| Unscripted speech | Yes | No |
| Prosody | Word stress, intonation, fluency | Fluency and rhythm on English and French packs |
| Exam prediction | IELTS, TOEFL | None |
| Mandarin | No | Initial / final / tone per syllable |
| Pricing | On request | Public plans: $10 / $50 / $150 per month |
| Self-serve signup | Request an API key | Yes |
| Audio retention | See vendor policy | Deleted after scoring; never used for training |
What to ask ELSA before you decide
Because ELSA's API pricing and limits are not published, the evaluation questions matter more than usual. Ask for: the per-request or per-minute price at your expected volume and the minimum commitment; the maximum recording length for scripted and unscripted modes; whether phoneme-level scores and timestamps are returned or only word-level feedback; the data-retention and training policy for learner audio; and whether an idempotent retry mechanism exists for mobile networks. Run the same twenty recordings — a few native speakers, a few learners with known errors — through both APIs and compare which native recordings each one flags.
Integration differences
Both are server-side REST APIs that take audio plus reference text for scripted tasks. TonePerfect's single endpoint returns the same structure for every language, so an English-first product that later adds Spanish or Mandarin changes nothing on the client:
curl https://api.toneperfect.app/v1/assess \
-H "Authorization: Bearer $TONEPERFECT_API_KEY" \
-H "Idempotency-Key: lesson-42-attempt-1" \
-F "audio=@take.wav" \
-F "text=I like sunny days" \
-F "language=en-US"Bottom line
If you teach English and want exam prediction, prosody feedback and unscripted scoring, talk to ELSA. If you teach more than one language — or Mandarin in particular — and want to start today on a published plan, TonePerfect is the practical choice.
Sources checked 10 September 2026: ELSA API page.