stable-audio

Stable Audio production guide

Stable Audio is Stability AI's generative-audio family for music and sound-design outputs, not speech, voice cloning, dialogue, or final mix/mastering. Use it when a project needs instrumental music, loops, stems/ideas, sound effects, foley-like assets, ambience, stingers, transitions, or style/continuation edits from rights-cleared audio. Route speech, dubbing, voiceover, transcript alignment, and loudness mastering to the appropriate speech/audio-post tools instead.

All volatile facts in this guide were verified on 2026-07-10 from Stability AI official pages, the Stability API OpenAPI specification, official model cards/repositories, and Stability policy pages.

Capability map

Documented facts:

• Hosted Stability API exposes two Stable Audio route families:
  • Stable Audio 2 endpoints under /v2beta/audio/stable-audio-2/..., with model choices stable-audio-2 and stable-audio-2.5.
  • Stable Audio 3 endpoints under /v2beta/audio/stable-audio/..., with model=stable-audio-3.
• Supported hosted workflows are text-to-audio, audio-to-audio, and inpainting/continuation.
• Hosted outputs are 44.1 kHz stereo, with mp3 or wav output format.
• Stable Audio 2/2.5 hosted endpoints return audio synchronously on success. Stable Audio 3 hosted endpoints return HTTP 202 with a generation id; poll GET /v2beta/audio/results/{id} until HTTP 200 returns the audio.
• Stable Audio 2/2.5 hosted duration limits are 1-190 seconds. Audio uploads for audio-to-audio and inpaint must be 6-190 seconds, mp3 or wav, and requests are capped at 50 MB.
• Stable Audio 3 hosted duration limits are 1-380 seconds. Audio uploads for audio-to-audio and inpaint must be 6-380 seconds, mp3 or wav, and requests are capped at 100 MB.
• Prompt length is capped at 10,000 characters.
• seed accepts 0 or omitted for random generation; explicit seeds may be recorded for reproducibility.
• steps differs by model: Stable Audio 2 accepts 30-100 steps and defaults to 50; Stable Audio 2.5 and Stable Audio 3 accept 4-8 steps and default to 8.
• cfg_scale ranges 1-25. API docs describe it as prompt-adherence strength; defaults are 7 for Stable Audio 2, 1 for Stable Audio 2.5, and 1 for Stable Audio 3. Treat it as a secondary control after prompt, duration, model, steps, and source-audio strategy.
• strength in audio-to-audio ranges 0-1 and controls source-audio influence. Stability describes 0 as identical to the input and 1 as equivalent to no audio influence.
• Inpaint uses mask_start and mask_end in seconds to choose the replacement/continuation segment.
• Hosted pricing, verified 2026-07-10: Stable Audio 2.0 is credits = 17 + 0.06 * steps per successful generation, usually 20 credits at the default 50 steps and 23 credits at 100 steps; Stable Audio 2.5 is 20 credits per successful result; Stable Audio 3.0 is 26 credits per successful result. Stability states failed generations are not charged. Stability pricing uses 1 credit = $0.01 and is subject to change.
• Stable Audio Open 1.0 is an open-weight text-to-audio model that generates variable-length stereo audio up to 47 seconds at 44.1 kHz.
• Stable Audio 3 open-weight releases include small-music, small-sfx, and medium; the official repository lists Small music/SFX as CPU-capable 433M-parameter models with 120s max length and Medium as a 1.4B CUDA model with 380s max length. Stable Audio 3 Large is API-only in the official repo.