LLM Reference

StepAudio 2.5 TTS

Released
2026-04-16
Last refreshed
2026-06-29
Status
Researched 45d ago
ProprietaryCommercial use: conditionalMultimodalVision

StepAudio 2.5 TTS is worth evaluating for vision when its provider route and context window match the workload.

Use it for

  • Teams evaluating vision
  • Buyers comparing 1 tracked provider route

Do not use it for

  • Strict JSON or tool-calling flows
Specifications
Released
2026-04-16
Specialization
text-to-speech
Openness
Proprietary
License
ProprietaryCommercial use: conditional
Weights
Not released
Code
Unknown
Created by

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

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

Cheapest of 1 route · StepFun

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.

StepAudio 2.5 TTS is a proprietary model in the StepAudio 2.5 family. The structured metadata tracks multimodal input and audio. This page tracks provider routes through StepFun. Headline tracked benchmarks include Artificial Analysis TTS Arena ELO 1187.0.

Top use-case fit

Vision

Included by capability and metadata signals in the decision map.

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.
BenchmarkScoreVersionSource
Artificial Analysis TTS Arena ELO1187.0arena-elohttps://artificialanalysis.ai/text-to-speech/leaderboard

Migration checks

No linked migration route is available for this model yet.

Frequently asked questions

When was StepAudio 2.5 TTS released?

StepAudio 2.5 TTS was released on 2026-04-16.

Which providers offer StepAudio 2.5 TTS?

StepAudio 2.5 TTS is available from 1 provider: StepFun.

What benchmarks has StepAudio 2.5 TTS been tested on?

StepAudio 2.5 TTS has been evaluated on 1 benchmark, including Artificial Analysis TTS Arena ELO.