OpenAI Whisper transcription online

What is OpenAI Whisper?

OpenAI Whisper is an open-source automatic speech recognition (ASR) model trained on 680,000 hours of multilingual audio collected from the public web. It was released by OpenAI in 2022 and has become a standard reference model for ASR research and production use. Whisper uses a transformer encoder-decoder architecture: the encoder reads an audio spectrogram, and the decoder generates text tokens, allowing it to transcribe or translate audio in a single forward pass.

Unlike earlier ASR systems that required language-specific models, Whisper handles 57 languages with a single model by detecting the language from the first 30 seconds of audio. This makes it practical for multilingual recordings, foreign-language interviews, and international content without any manual configuration. It also supports translation: it can return a transcript directly in English regardless of the source language.

convert.express runs Whisper through the OpenAI API. You upload your file, it is processed server-side, and the transcript is returned to your browser. Files are deleted automatically after 24 hours. The API terms of service prohibit OpenAI from using your audio to train models.

Whisper vs. MAI-Transcribe 1.5

convert.express offers two models. Here is how they compare. Full comparison →

Frequently asked questions

What is OpenAI Whisper and how does it work?

OpenAI Whisper is an open-source automatic speech recognition (ASR) model trained on 680,000 hours of multilingual audio. It converts spoken audio to text by processing the audio spectrogram through a transformer encoder-decoder architecture. convert.express runs Whisper via the OpenAI API — you upload the file, it is processed server-side, and the transcript is returned to you.

How accurate is Whisper transcription?

Whisper achieves roughly 5–8% word error rate (WER) on English and other well-resourced languages, which means roughly 92–95 words out of every 100 are transcribed correctly on clean audio. Accuracy varies with recording quality, speaker accent, background noise, and the specific language. Technical terminology and unusual proper nouns are the most common sources of error.

Which languages does Whisper support?

Whisper supports 57 languages including Arabic, Chinese, Dutch, English, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Turkish, Ukrainian, and more. It includes coverage for minority and regional languages not covered by some commercial ASR systems. The language is detected automatically — you do not need to specify it manually.

Can Whisper translate recordings into English?

Yes. When you select the translation option in convert.express, Whisper transcribes the audio and returns the result in English regardless of the source language. This is useful for quickly understanding content in a foreign language without needing a separate translation step.

How long does Whisper transcription take?

Whisper processes audio at roughly 60–90 seconds per hour of recording. A 30-minute interview takes around 45–60 seconds to return. A 5-minute voice memo is typically ready in under 15 seconds. Processing time depends on file size and server load.

When should I choose Whisper over MAI-Transcribe 1.5?

Choose Whisper when: you need a language that MAI-Transcribe 1.5 does not yet cover (Whisper supports 57 languages vs. 43 for MAI); you need English translation of a foreign-language recording; or you prefer a generally-available model with no preview caveats. MAI-Transcribe 1.5 is faster and more accurate on its supported languages, but is still in public preview.