Soniox vs Speechmatics for Vietnamese
speech-to-text and translation
Accurate, real-time transcription and translation for Vietnamese.
Developers choose Soniox for real-time fluency in Vietnamese and beyond
Vietnamese is spoken by 95 million people worldwide — primarily in Vietnam, with speakers around the world. Developers building for Vietnamese need accuracy, speed, and global scalability. Soniox provides one API that works across 60+ languages – including Vietnamese – with real-time transcription and any-to-any translation built in.
Speechmatics supports many languages, but accuracy in real-world Vietnamese use cases often lags. With Soniox, you get production-ready results from day one.
Higher accuracy in Vietnamese
Soniox consistently beats Speechmatics in benchmarks, with lower word error rates on real-world audio. Vietnamese WER 5.4% vs 14.2% for Speechmatics.
Zero delay
Transcribe Vietnamese conversations instantly, not seconds later. Speechmatics streams in larger chunks, which makes apps feel delayed.
Unified API
Soniox handles both transcription and two-way translation across 60+ languages, so you can build for Vietnamese and scale worldwide. Speechmatics only covers transcription.
Helping startups and enterprises ship real world voice apps
See the difference for yourself
Don’t just take our word for it. Run the same Vietnamese audio through Soniox and Speechmatics in real time and compare live results, side by side.
This demo isn’t pre-recorded. It makes real API calls to Speechmatics and Soniox in real time, with each service tuned for its best performance. The framework is open source, so you can inspect or run it yourself.
Soniox vs Speechmatics at a glance
| Feature | Sonioxstt-rt-preview-v2 | Speechmaticsrealtime-enhanced |
|---|---|---|
| Single Multilingual Model | ||
| Language Hints | ||
| Language Identification | ||
| Speaker Diarization | ||
| Customization | ||
| Timestamps | ||
| Confidence Scores | ||
| Translation One Way | ||
| Translation Two Way | ||
| Endpoint Detection | ||
| Manual Finalization |
And the benchmarks back it up.
In a 2025 study across 60 languages and real-world YouTube audio, Soniox reached 5.4% WER in Vietnamese vs 8.9% for Speechmatics.
View the full benchmark report »
From transcripts to real-time, global speech
Precision built for real-world speech.
Soniox was benchmarked across 60 languages, including Vietnamese, and achieved state-of-the-art accuracy. That means fewer mistakes in fast speech, accents, and messy environments.
Speechmatics performs well on clean datasets, but accuracy in real-world Vietnamese audio (calls, meetings, podcasts).
Real-time that truly feels live.
Soniox streams Vietnamese speech into text with ultra-low latency. Apps feel live, enabling natural conversation and instant captions.
Speechmatics transcriptions often finalize with noticeable delay, which makes live experiences less usable.
Global-ready from the start.
Soniox translates between Vietnamese and 60+ other languages in real time. Developers don’t need separate APIs or extra integration.
Speechmatics requires third-party translation, adding latency, cost, and complexity.
Simple pricing that scales.
At ~$0.10–0.12/hr, Soniox includes transcription, translation, diarization, timestamps, and confidence in one price.
Speechmatics charges more per hour and only covers transcription. Translation requires another vendor.
Pay 2-3x less than Speechmatics
With Soniox, transcription, translation, diarization, timestamps, and confidence are all included in one price. Speechmatics charges more per hour and only covers transcription. Translation (including Vietnamese) requires another service.
Effective hourly cost (typical speech)
Soniox: ~$0.10/hour (async), ~$0.12/hour (streaming)
Speechmatics: ~$0.25–0.35/hour depending on model and volume
| Soniox (async) | Soniox (streaming) | Speechmatics (typical) | |
|---|---|---|---|
| 100 hours | ~$10 | ~$12 | ~$25-35 |
| 1,000 hours | ~$100 | ~$120 | ~$250-350 |
| 1,000 hours | ~$1,000 | ~$1,200 | ~$2,500-3,500 |
Takeaway: Soniox costs 2–3x less than Speechmatics, while also including translation, diarization, and other features by default.
Notes:
- Soniox bills per token, which works out to the effective hourly rates above for typical conversational speech.
- Speechmatics pricing varies by model and volume tier, but charges per minute/hour for transcription only.
- All comparisons use publicly listed rates as of 2025.
Frequently asked questions about Soniox vs Speechmatics
Does Soniox support Vietnamese?
Yes. Soniox fully supports transcription and translation for Vietnamese, with production-ready accuracy and real-time performance.
Can Soniox handle code-switching between Vietnamese and English?
Yes. Soniox automatically detects and transcribes mixed speech, switching between Vietnamese and English mid-conversation. Speechmatics requires preselecting one language per request.
Is Soniox cheaper than Speechmatics?
Yes. Soniox costs ~$0.10–0.12/hr, while Speechmatics typically charges ~$0.25–0.35/hr depending on model and volume. That makes Soniox about 2–3x less expensive.
Does Speechmatics support translation?
No. Speechmatics provides transcription only. Soniox includes two-way, in-stream translation across 60+ languages in the same API call.
How does Soniox streaming compare to Speechmatics?
Soniox streams token by token in milliseconds, with refinements, manual finalization, and endpoint detection. Speechmatics streams in larger segments, which can feel slower for live use cases.
Does Speechmatics support diarization and timestamps?
Yes, but Soniox provides them in real time with more structured outputs.
Can Soniox handle multiple languages in one stream?
Yes. Soniox auto-detects and supports mid-conversation shifts. Speechmatics requires you to pre-select a single language per request.
Soniox surpasses Speechmatics in any language
Get the most accurate, real-time speech-to-text transcription and translation in 60+ languages
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