New: Soniox v5 Async is here
Get the AppBuild with API

Soniox vs OpenAI for real-time speech translation

Test Soniox real-time translation against OpenAI GPT Realtime Translate on the same audio. Hear the difference, then compare pricing, language coverage, and translation modes, before you commit to an API.

Open in a new tab to easily compare providers in real-time.

Compare now

Estimate your speech translation cost

Soniox bills per token across one model that handles transcription and translation together. Set your monthly audio volume below to compare Soniox and OpenAI pay-as-you-go speech translation pricing side by side.

Pricing calculator

Stop overpaying for speech AI

SonioxvsOpenAI

1,000 hours of audio / month

1025501002505001k2.5k5k10k100k

Pricing assumptions

Based on public pay-as-you-go pricing. Enterprise discounts and committed-use contracts may differ. Some providers charge separately for certain features. The calculator uses the public price for the provider configuration that most closely matches Soniox. For TTS 1000 characters / minute is used as a reference.

At 1,000 hours per month, Soniox runs around $180 for real-time speech translation or $160 for async speech translation.

Soniox vs OpenAI GPT Realtime Translate at a glance

Each row lists the same capability for both providers, sourced from public docs and pricing pages.

Capability
Soniox
OpenAI GPT Realtime Translate
Translation modes
One-way and two-way
One-way only
Source languages
60+
74 (Whisper-derived)
Target output languages
60+ (3,600 pairs)
13 fixed targets
Bilingual conversation
Yes, native two-way
No
Diarization in same stream
Yes
No
Billing
Per token, one API
Per audio minute, plus Realtime Whisper for source transcript
STT translation ($/hour)
~$0.18
$2.04 ($3.06 with Realtime Whisper)
Speech-to-speech ($/hour)
~$0.82
$2.04
Translation in same connection
Yes
Yes, via Realtime API

Language coverage: 3,600 pairs vs 13 target outputs

Coverage diverges sharply on the output side. Soniox treats translation as any-to-any across its supported set. OpenAI GPT Realtime Translate fixes the target list at 13 languages.

Soniox

60+

Languages, both as source and target.

3,600

Language pairs, any-to-any.

OpenAI GPT Realtime Translate

74

Input languages, derived from Whisper.

13

Fixed target output languages:
en, es, pt, fr, de, it, ja, ko, zh, ru, hi, id, vi.

One-way and two-way translation support

Soniox ships both translation modes. OpenAI GPT Realtime Translate ships one.

Soniox: both modes

One-way translation streams every speaker into a single target language.

Two-way runs a live bilingual conversation between two languages. Each side speaks naturally and hears the other in their own language.

OpenAI: one-way only

GPT Realtime Translate translates speech into one configured target language per session.

Bilingual back and forth is not a built-in mode on the Realtime API.

What to compare in real-time speech translation?

OpenAI GPT Realtime Translate ships translation through the Realtime API alongside voice output. Soniox runs a single streaming pipeline that returns transcript and translation tokens together, with voice output optionaly enabled by using Soniox Text-to-Speech.

Besides translation accuracy, the difference that matters in production is obviously cost, how many target languages you can translate into, and which additional features each one ships out of the box.

FAQ

Is real-time translation cheaper on Soniox or OpenAI?
Yes, by a wide margin. Soniox bills per token: real-time speech-to-text translation works out to ~$0.18/hour, and full speech-to-speech (with Soniox Text-to-Speech) to ~$0.82/hour. OpenAI GPT Realtime Translate is billed by audio duration at $0.034 per minute, which is $2.04/hour. If you also want the source-language transcript, you add Realtime Whisper at $0.017 per minute ($1.02/hour extra). That puts Soniox at roughly 17x cheaper for STT translation and ~2.5x cheaper for speech-to-speech.
How many languages can each one translate into?
Soniox supports 60+ source and 60+ target languages, yielding 3,600 any-to-any pairs. OpenAI GPT Realtime Translate accepts 74 input languages (Whisper-derived) but outputs only 13 fixed targets: en, es, pt, fr, de, it, ja, ko, zh, ru, hi, id, vi.
Does OpenAI support two-way bilingual conversation?
Not as a built-in mode. GPT Realtime Translate translates into one configured target per session. Soniox supports two-way translation natively, with each side speaking and hearing in their own language on the same WebSocket.
Does GPT Realtime Translate return the source-language transcript?
Only the translated transcript arrives as part of GPT Realtime Translate. If you also need the words as they were originally spoken, you run Realtime Whisper as a second paid model at $0.017 per audio minute. Soniox returns the source-language transcript and the translation in the same stream, with no extra model or cost.
Does Soniox identify speakers when translating?
Yes. Soniox returns speaker labels for diarized conversations alongside transcript and translation tokens, so a translated meeting or call can still attribute each line to the right person. GPT Realtime Translate does not return speaker labels.
What kinds of languages does GPT Realtime Translate output to?
13 fixed target languages: English, Spanish, Portuguese, French, German, Italian, Japanese, Korean, Chinese, Russian, Hindi, Indonesian, and Vietnamese. Soniox supports 60+ target languages and 3,600 any-to-any pairs, so translating between two non-English languages (for example, Polish to Korean) is a first-class case on Soniox.

Start translating in real time

Create an account instantly, or contact us to design a custom package for your business.

Build with API

Documentation

Get up and running in minutes and spend your time building the product, not wrestling with the API.

Explore docs

See what you’ll pay

Pay only for what you use with our flexible pricing. Built to scale with you.

Pricing details