Tasks and inputs
StepAudio 3 TTS is listed for Text-to-speech. It accepts text and produces audio. Use the publisher’s input format and preprocessing for your chosen deployment.
StepAudio 3 TTS converts text to expressive speech, with ordinary synthesis and a WebSocket streaming interface.
The specification score summarizes recorded features and limits. It is not a benchmark result.
Recorded modality support shows what this model can accept and produce. An undocumented modality is shown as unknown rather than assumed to be unsupported.
Accepts
Produces
StepAudio 3 TTS converts text to expressive speech, with ordinary synthesis and a WebSocket streaming interface.
StepAudio 3 TTS generates speech from supplied text. The publisher documents control over delivery and a streaming path intended for responsive voice interfaces. A narration workflow can use the non-streaming speech endpoint; an application that starts playback while generation continues uses the realtime audio WebSocket.
Test a short passage containing names, numbers, abbreviations and an intentional pause. Listen for intelligibility, pacing and consistency across successive segments. A conversational application also needs to stop or discard queued audio when the user interrupts. The audio transport is only one part of that playback workflow.
The direct rate card lists $0.36 per 10,000 characters for synthesis and $1.50 for a successful production voice clone. StepFun’s counting rules treat Chinese characters, English letters and punctuation differently. Estimate cost from the service’s actual usage rules and include regenerated passages. These character prices should not be placed in the model table’s per-million-token columns.
Compare the same approved script through ordinary synthesis and streaming playback. Measure time to the first audible segment, gaps between chunks and total completion time. Keep the selected voice and output format constant so the comparison reveals differences in delivery instead of differences in the brief.
Compare the model on the work you need to complete.
StepAudio 3 TTS is listed for Text-to-speech. It accepts text and produces audio. Use the publisher’s input format and preprocessing for your chosen deployment.
Compare pronunciation, voice consistency and time to the first playable audio. Check the service’s billing unit for the actual script.
Use the model identifier and account requirements for the selected API route. Confirm its request limits and output format with one complete task before connecting a larger workflow.
These records share a directory category. Check the source card, output type and deployment requirements before treating a model as a replacement.
Gemini 3.8 Flash-Lite TTS converts supplied text into speech through the Gemini API. It is a candidate for read-aloud features and repeated single-speaker audio jobs.
Gemini 3.8 Flash TTS turns a supplied text transcript into audio. It is a speech-generation model for narration and dialogue, with speaker and style information supplied separately from the words to be spoken.
xAI
Grok Voice TTS 1.0 from xAI: Convert text into spoken audio with a single API call. The API supports a rich set of expressive voices, inline speech tags for fine-grained delivery control, and output formats from high-fidelity MP3 to telephony-optimized μ-law.
OpenAI
GPT-Realtime-2.1 from OpenAI: Realtime speech-to-speech model with configurable reasoning, tool use, and robust voice-agent behavior.
Gemini 3.5 Live Translate Preview from Google: Low-latency audio-to-audio model for real-time speech translation across 70+ languages.
Gemini 3.1 Flash TTS Preview from Google: Low-latency speech generation with steerable prompts and expressive audio tags.