StepAudio 2.5 TTS

Released
2026-04-16
Last refreshed
2026-06-29
Status
Researched 135d ago
ProprietaryCommercial use: conditionalMultimodalVision
StepFun releases · 7 in the last 12 months · this family litChangelog →
Specifications
Released
2026-04-16
Specialization
text-to-speech
Openness
Proprietary
License
ProprietaryCommercial use: conditional
Weights
Not released
Code
Unknown
Created by
StepFun

One of China's leading AI 'Six Tigers'.

Shanghai, China
Founded 2023
Website
Pricing
Output / 1M
-
Input / 1M
-

Cheapest of 1 route · StepFun

Providers(1)
StepFun
View 1 provider route
Links
Website

About

StepAudio 2.5 TTS is StepFun's contextual text-to-speech model with fine-grained expressive control. Unlike tag-based TTS systems, it accepts plain natural language instructions to control emotion, pacing, pauses, and delivery. Supports zero-shot voice cloning with full timbre and emotion control. Priced at $0.85 per 10,000 characters (input text). Supports Chinese and English. Available via StepFun API (model: step-audio-2.5-tts). Part of the unified StepAudio 2.5 architecture described in arXiv:2605.23463.

Provider price ladder

Compare API pricing across 1 providers for input and output tokens, batch, and cached reads when available.

ProviderInput / 1MOutput / 1MRoute
StepFun--
ServerlessPartial

Capabilities

MultimodalAudio

Benchmark peer barsfor Vision

No task-mapped benchmark peers are available for this model yet.

Benchmark scores(1)

Scores are benchmark-specific and are direction-aware: the same numeric gap can mean very different outcomes across suites. Use the leaderboard context and this model's provider route to decide whether the winning margin is meaningful for your workload.
BenchmarkScoreVersionEvaluationSource
Artificial Analysis TTS Arena ELO1187.0arena-eloObserved 2026-05-24—Source

Migration checks

No linked migration route is available for this model yet.