Is S2.1 Pro Free (free) free?

Yes. The pricing shown on this page for S2.1 Pro Free (free) is zero, so you are not charged for generated speech. Free endpoints are rate limited — see the rate limit docs.

What inputs and outputs does S2.1 Pro Free (free) support?

S2.1 Pro Free (free) accepts text as input and returns generated speech audio.

Which providers serve S2.1 Pro Free (free)?

S2.1 Pro Free (free) is served by 1 provider on OpenRouter: Fish Audio.

What other speech models does Fish Audio have?

Drama 3, S1, S2 Pro and 1 more are other speech models from Fish Audio.

When was S2.1 Pro Free (free) released?

S2.1 Pro Free (free) was released on July 29, 2026.

Fish Audio: S2.1 Pro Free (free)

fish-audio/s2.1-pro-free:free

Benchmarks Compare

S2.1 Pro Free is the no-cost variant of Fish Audio S2.1 Pro, intended for testing, prototyping, and low-volume applications. It provides the same synthesis capabilities without production latency or availability guarantees.

Modalities

Price

Free

Released

Jul 29, 2026

Providers

This model is hosted by one provider. OpenRouter forwards every request without routing.

Latency


	Free	Free	0.63s	99.72%

Input FreeOutput Free
0.63s latency99.72% uptime

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Uptime (3d)

100.00%

Availability (3d)

99.82%

Availability over the last 3 days

Last 72 hours

Availability 99.82%

3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability

99.91%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Apps

Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.

Lumiverse

new

1.48Mtokens

Formula AI

new

1.4Mtokens

medicine.kazimiri.com blanking read-back

new

520Ktokens

Hermes Agent

Hermes Agent is an open-source, self-improving AI agent by Nous Research that runs persistently with memory across sessions, and builds reusable skills from experience. It comes with 40+ built-in tools, including web search, browser automation, and vision, plus scheduled automations and subagents.

496Ktokens

MemoTube

new

341Ktokens

Rest of OpenRouter

900K

Top 5 Apps

83K

Not currently available through EU in-region routing. In-region routing docs

More models from fish-audio

Drama 3

Drama 3 is a text-to-speech model from Fish Audio built for directed voice performances. You write the direction in plain language in square brackets before a line, such as [nervous, barely holding it together], and can add sounds and pauses inline or change the delivery of specific words with paired tags like <whisper>.

It supports multi-speaker scenes in one request, switching language mid-sentence across 80+ languages in the same voice, and phoneme tags for pinning pronunciation of names and terms.

Speech$10/M UTF-8 bytes

Transcribe 1 Pro

Transcribe 1 Pro is a speech-to-text model from Fish Audio tuned for interviews, meetings, and podcasts. It labels speakers with inline speaker markers, preserves emotion and vocal-event cues such as [laughter], detects language automatically, and can return timestamped word-level segments.

Transcription$0.0001/second

Transcribe 1

Transcribe 1 is a speech-to-text model from Fish Audio. It is suited for audio transcription with automatic language detection and can return timestamped word-level segments when alignment details are requested.

Transcription$0.0001/second

S1 is a multilingual text-to-speech model from Fish Audio. It is suited for voice applications that need broad emotional expression, using parenthetical controls to guide speaking style across its supported languages.

Speech$15/M UTF-8 bytes

S2 Pro

S2 Pro is a multilingual text-to-speech model from Fish Audio. It is suited for expressive narration and multi-speaker dialogue, with natural-language controls for speaking style and emotion.

Speech$15/M UTF-8 bytes

S2.1 Pro Free (free)

SpeechFree

S2.1 Pro

S2.1 Pro is a production-oriented text-to-speech model from Fish Audio. It is suited for multilingual voice applications, expressive narration, and dialogue synthesis, with open-ended natural-language controls for speaking style and emotion.

Speech$15/M UTF-8 bytes

Fish Audio: S2.1 Pro Free (free)

Playground

Providers

Performance

Uptime

Availability over the last 3 days

Availability over the last 24 hours

Apps

Activity

API

Frequently asked questions

Explore more models

More models from fish-audio

More models from fish-audio

Fish Audio: S2.1 Pro Free (free)

Playground

Providers

Performance

Uptime

Availability over the last 3 days

Availability over the last 24 hours

Apps

Activity

API

Frequently asked questions

What is S2.1 Pro Free (free)?

Is S2.1 Pro Free (free) free?

What inputs and outputs does S2.1 Pro Free (free) support?

Which providers serve S2.1 Pro Free (free)?

What other speech models does Fish Audio have?

When was S2.1 Pro Free (free) released?

Explore more models

More models from fish-audio

More models from fish-audio