Developer guide

Speech to Text API: Audio Transcription Workflow Fish Audio

Build a speech to text workflow from audio upload to usable transcript, with language detection, speaker review, privacy, retries and production QA.

2026/10/20

A speech to text API turns recorded audio into text your application can index, search, caption or edit. Production quality depends as much on input preparation and transcript cleanup as on the model. Fish Audio’s workspace can transcribe uploaded audio and video and return text with language and multispeaker context, while the broader speech to text guide explains the user-facing workflow.

A microphone feeding a translucent coral voice ribbon into an abstract transcript sheet for a speech to text API

What should a transcription pipeline do?

The pipeline has five visible stages:

  1. Validate and accept an authorized upload.
  2. Extract or normalize the audio track.
  3. Submit the transcription request.
  4. Store the result and expose processing status.
  5. Let a person review names, speaker changes and unclear passages.

The API contract may change, so build around the capabilities described in the current product rather than hard-coding a guessed JSON response from an old tutorial.

How should you prepare the audio?

A clean audio source produces a better transcript. For interviews, remove music beds and strong room echo when possible. For video files, use the original audio rather than recording the output of laptop speakers.

Input problemEffectPractical fix
Heavy background musicMissed and invented wordsUse a clean dialogue track
Multiple speakers on one microphoneWeak speaker separationRecord each speaker separately if the workflow allows
Long silenceWasted processing timeTrim non-content sections
Wrong languageGarbled textSet the language when it is known
Technical vocabularyUnreliable termsSupply a glossary in review notes

Keep the original file. A compressed preview may be easy to upload but can lose the detail needed for a later retry.

How do you handle speakers and timestamps?

Speaker separation improves readability but is not a substitute for editorial review. Short interruptions, overlapping speech and off-microphone comments can place a line under the wrong speaker. Label speakers consistently before publishing a transcript, and listen back wherever a quote will appear in public.

Timestamp support depends on the current contract. If your application needs captions or clip search, verify the available timing fields before designing the data model. Do not assume every transcription response contains word-level timings.

How much does transcription cost?

The product currently charges a small fixed credit amount per transcription job, which is different from text-to-speech’s per-character model. That makes job count the useful planning unit for a transcript archive.

WorkloadJob countPlanning note
Ten 30-minute interviews10Review speaker labels and names
A 40-episode podcast season40Batch by episode, not the full season
Weekly team recordings4–5 per monthAutomate retention and deletion
Video course modulesOne per moduleReview captions against the final edit

The $9 Starter pack includes 1,000 credits, but check the current upload cost and limits before building a large batch estimate.

How do you turn a transcript into publishable text?

Raw speech includes false starts, filler words, repeated thoughts and references to slides the reader cannot see. A useful editorial pass:

  • Remove filler that adds no meaning.
  • Repair sentence boundaries created by natural pauses.
  • Replace vague pronouns with the person or object intended.
  • Verify names, numbers and product terms.
  • Add context that was visible on screen during the recording.
  • Keep quotes close to the speaker’s original wording.

For podcast teams, the podcast transcript generator guide covers a complete episode workflow. For spoken content that needs a new voice, start with AI podcast voice.

How should errors and retries work?

Authentication, unsupported media, file-size limits and malformed requests should fail immediately with an actionable message. Network failures and temporary provider errors can be retried with a bounded backoff. Store a content hash with each job so the same unchanged file is not submitted twice by accident.

If processing is asynchronous, expose a durable status instead of holding a browser request open for several minutes. A user should see queued, processing, completed or failed, with a way to recover the completed transcript.

What privacy controls are required?

Audio can contain personal data, confidential meetings or biometric clues. Build retention into the workflow from day one:

  • Limit access to the original upload and transcript.
  • Encrypt storage and rotate any signed download links.
  • Delete temporary audio when it has served its purpose.
  • Record the legal basis or consent for processing.
  • Keep provider logs separate from user-facing analytics.
  • Avoid placing full transcripts in error-monitoring tools.

The site’s privacy policy describes the public service context, but your own application remains responsible for the data it uploads and stores.

What should you test before processing real users?

Test short and long recordings, mono and stereo tracks, multiple languages, strong accents, background noise and files near the upload limit. Verify failure states, retry behavior, speaker labels and deletion. Then run a human review on one real sample from each content type you plan to support.

For the user-facing product path, see Fish Audio API. For speech generation after transcription, connect back to the AI voice generator guide.

What should the QA review compare?

Compare the transcript with the source audio at three levels. First check names, numbers, dates and product terms. Then check speaker turns and interruptions. Finally read the whole transcript for meaning: a sentence can contain the right words and still reverse the relationship between “before” and “after.”

Keep a small evaluation set covering your most important audio conditions. Re-run it when the media type, language settings or upload pipeline changes. A short regression set catches more useful failures than repeatedly testing one clean studio recording.

Publish the evaluation notes with the job, not only in a developer ticket. Editors need to know which names were uncertain and which speaker labels were manually changed. That context makes the transcript auditable and helps the next upload receive better source audio.

Frequently asked questions

What does a speech to text API return?

A transcription workflow turns uploaded audio or video into text. Depending on the current product contract, the result can include the transcript, inferred language and speaker context; check the workspace for the exact fields available to your account.

What file types can I transcribe?

The upload workflow accepts common audio and video media types, with size limits shown by the product. Prefer a clean mono audio track for interviews, but keep the original file if you may need to regenerate the transcript.

How much does transcription cost?

A transcription job currently costs a small fixed number of credits rather than being metered by generated characters. Check the upload screen before processing a large archive so you can estimate the job count.

Can I publish the transcript as an article?

Yes, after editing. Spoken language contains false starts, repeated phrases and context that only makes sense in audio. Turn the transcript into readable copy before publishing it.

How should I store uploaded audio?

Treat it as sensitive user data. Set a retention period, restrict access, record consent where required and delete temporary files when the transcript no longer needs the source audio.

Speech to Text API: Audio Transcription Workflow | Fish Audio