FISH AUDIOTEXT-TO-SPEECH51,136 SAMPLES / 30 DAYSLAST RUN AUG 28, 2026, 21:30 UTC

S2.1 Pro Free text-to-speech benchmarks

Name: S2.1 Pro Free — Fish Audio text-to-speech benchmark results
Creator: Coval

S2.1 Pro Free is Fish Audio's free service route for the S2.1 Pro family.

Time to First Audio#29 / 30: 806ms
TTFA Network Roundtrip#27 / 28: 905ms
TTFA Leading Silence#2 / 28: 16ms
Word Error Rate#8 / 30: 4.7%

Overview

Separate results show the latency and intelligibility of the free endpoint without combining it with the production route.

S2.1 Pro Free is tested every day on a fixed set of text prompts, measuring how quickly audible speech starts and how intelligible the result is.

Technical specifications

Made by: Fish Audio
Hosted by: Fish Audio
Source: Official API
Licensing: Proprietary
Deployment: Cloud
Region: US
Features: Multilingual, Voice cloning, Emotion control

How S2.1 Pro Free ranks

Full TTS dashboard

Time to First Audio — every measured TTS modelMilliseconds · lower is better · 30-day average

#1Palabra TTS v1116 ms
#2vui124 ms
#3TTS Flash 2128 ms
#4TTS 2176 ms
#5Blizzard235 ms
#6Neural236 ms
#7Mist v3256 ms
#8TTS Rt v2262 ms
#9Sonic 3.5274 ms
#10TTS RT v1275 ms
#11Dragon HD Latest310 ms
#12Coda313 ms
#13Aura 2328 ms
#14S2.1 Pro374 ms
#15Default384 ms
#16Speech 2.8 Turbo411 ms
#17Eleven v3 Conversational412 ms
#18Grok TTS420 ms
#19S1434 ms
#20Flash v2.5455 ms
#21Speech 2.8 HD460 ms
#22Sonic 3.6466 ms
#23Simba 3.2484 ms
#24Chirp 3 HD512 ms
#25Simba 3.0526 ms
#26Falcon 2549 ms
#27Lightning v3.1 Pro586 ms
#28Qwen3 TTS Flash Realtime645 ms
#29S2.1 Pro Free806 ms

Show all 30 models

#30GPT-4o mini TTS1075 ms

median of all models · 397 ms

TTS models over the last 30 days, ranked on Time to First Audio.
#	Model	Host	TTFA	WER	Samples
1	Palabra TTS v1	Palabra	116 ms	5.9%	14,396
2	vui	Fluxions	124 ms		8,624
3	TTS Flash 2	Inworld AI	128 ms		8,719
4	TTS 2	Inworld AI	176 ms	4.8%	14,529
5	Blizzard	Lmnt	235 ms	7.4%	14,117
6	Neural	Azure	236 ms	4.3%	3,350
7	Mist v3	Rime	256 ms	6.3%	14,524
8	TTS Rt v2	Soniox	262 ms		8,849
9	Sonic 3.5	Cartesia	274 ms	6.1%	14,513
10	TTS RT v1	Soniox	275 ms	3.7%	14,528
11	Dragon HD Latest	Azure	310 ms	5.1%	3,350
12	Coda	Rime	313 ms	5.2%	14,523
13	Aura 2	Deepgram	328 ms	5.3%	14,501
14	S2.1 Pro	Fish Audio	374 ms		10,222
15	Default	Gradium	384 ms	4.6%	14,002
16	Speech 2.8 Turbo	MiniMax	411 ms	4.8%	1,997
17	Eleven v3 Conversational	ElevenLabs	412 ms		6,750
18	Grok TTS	xAI	420 ms	4.7%	14,524
19	S1	Fish Audio	434 ms	4.9%	10,236
20	Flash v2.5	ElevenLabs	455 ms	6.7%	9,259
21	Speech 2.8 HD	MiniMax	460 ms		1,995
22	Sonic 3.6	Cartesia	466 ms		560
23	Simba 3.2	Speechify	484 ms	4.7%	14,525
24	Chirp 3 HD	Google	512 ms	5.2%	14,530
25	Simba 3.0	Speechify	526 ms	5.3%	14,526
26	Falcon 2	Murf	549 ms		10,229
27	Lightning v3.1 Pro	Smallest	586 ms	4.4%	14,515
28	Qwen3 TTS Flash Realtime	Alibaba	645 ms	8.8%	14,530
29	S2.1 Pro Free	Fish Audio	806 ms	4.7%	14,464
30	GPT-4o mini TTS	OpenAI	1075 ms	4.8%	14,517

Under-sampled models are excluded; tied models share a place. Dotted WER values split into substitutions, deletions and insertions on hover or tap.

Highest relative placement: 8th of 30 on Word Error Rate.

Averages and tail latency

Averages hide slow outliers — these are the distributions behind each figure.

S2.1 Pro Free latency distributionMilliseconds · shared axis across metrics · last 30 days

Time to First Audiop50 372 ms · p99 9081 ms
TTFA Network Roundtripp50 367 ms · p99 11606 ms
TTFA Leading Silencep50 7 ms · p99 104 ms

band p25–p75 · tick p50 · whisker to p99 with p90 and p95 stops

Average and percentile values per metric, with the number of samples behind each row.
Metric	Average	p25	p50	p75	p90	p95	p99	Samples
Time to First Audio	806 ms	333 ms	372 ms	483 ms	1101 ms	1771 ms	9081 ms	14,464
TTFA Network Roundtrip	905 ms	325 ms	367 ms	557 ms	1328 ms	2257 ms	11606 ms	11,104
TTFA Leading Silence	16 ms	2 ms	7 ms	20 ms	45 ms	72 ms	104 ms	11,104
Word Error Rate	4.7%	0.0%	0.0%	7.7%	18.8%	21.4%	35.7%	14,464

Last 30 days

Daily medians from the same measurement runs · gaps are days without qualifying runs.

Time to First Audio — daily p50Line p50 · band p25–p75 · UTC days

Word Error Rate — daily averageDaily average · UTC days

Time to First Audio by dataset

S2.1 Pro Free by test conditionMilliseconds · lower is better · best condition first

Text prompts806 ms

Time to First Audio per dataset, with the number of samples behind each figure.
Dataset	TTFA	Samples
Text prompts	806 ms	14,464

Strongest condition: Text prompts at 806 ms · weakest: Text prompts at 806 ms.

Limits of this comparison

The free route is measured separately from the production route using the same prompts.

Free-tier capacity and policy can change, so readers should use the live window rather than treating one snapshot as permanent.

Official sources

Fish Audio text-to-speech API (documentation)

Results are re-measured daily using fixed datasets and reported over a rolling 30-day window. Same datasets, prompts and metric definitions for every model, measured by Coval’s open-source runner. Full methodology on the overview.

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