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The STT Playground makes it easy to try out Inworld’s Speech-to-Text capabilities through an interactive playground. Use it to compare transcription models, test language hints and custom vocabulary, and watch Voice Profile analyze the speaker in real time — all before writing a line of code. STT Playground

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Get Started

1

Go to Inworld Portal

In Portal, select Speech-to-Text from the left-hand side panel.
2

Choose a model

Click the model dropdown at the top of the playground to browse available models. Each entry shows its provider and language coverage — from Inworld’s own inworld/inworld-stt-1 to models from Groq, AssemblyAI, Soniox, and Deepgram. See the model comparison for details on each.
3

Record or upload audio

Press the mic button to transcribe live from your microphone, or use the upload button to transcribe an audio file. The status bar shows Ready when the playground can accept audio and Listening… while recording.Input options depend on the selected model’s endpoint support — for example, groq/whisper-large-v3 transcribes uploaded files only (no live streaming). See the model comparison for each model’s endpoints.
4

Review the transcript

The transcript appears in real time as you speak. When you’re done, use the copy button to grab the text, or the code button to view the equivalent API request.

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Advanced Features

For greater control over transcription, try the following:
  1. Language hint — The Language dropdown defaults to Auto-detect, which recognizes the spoken language automatically. Select a specific language to give the model a hint when you know the audio’s language in advance — this generally improves accuracy, especially for short utterances. See Language Support for how hints behave.
  2. Custom vocabulary — Click Vocabulary to add key terms (names, jargon, acronyms) that bias recognition toward them. Terms are added as chips, and the button shows how many are active. This is a soft bias rather than a hard keyword lock — test it on the terms the baseline actually misses. The equivalent API field is prompts.
  3. Voice Profile — The panel on the right analyzes the speaker alongside transcription, showing Age, Accent, Voice Pitch, Vocal Style, and Emotion, each with a confidence score. It populates after transcription begins. See Voice Profiles for the full category reference.

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From Playground to Code

Click Integrate (top right) — or Get integration code in the Voice Profile panel — to generate an API request matching your current playground configuration: model, language hint, vocabulary, and Voice Profile settings.

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Next Steps

Ready to build? Here’s where to go next.

Quickstart

Make your first STT API call in minutes.

Voice Profiles

Analyze speaker characteristics alongside transcription.

Language Support

Language coverage and hinting behavior.