Article summary — original
Hugging Face Launches Open TTS Leaderboard for Scalable Multilingual and Voice Cloning Evaluation
Hugging Face has introduced the Open TTS Leaderboard to address fragmented text-to-speech evaluation, using objective metrics across intelligibility, latency, and speaker similarity to benchmark open-source models rapidly.
Arena-based human evaluations cannot scale with the more than 8,000 text-to-speech models on the Hugging Face Hub, leaving open-weights models underrepresented.
The new leaderboard reduces evaluation times from weeks to hours by using Qwen3 ASR for error rates, H200 GPU and CPU timings for speed, and WavLM embeddings for voice cloning similarity.
Evaluations span English and multilingual datasets including Seed TTS Eval and CV3 Eval, while dedicated tabs assess streaming time-to-first-audio and user listening tests.
Addressing Arena Scalability with Objective Metrics
While human preference scoring remains the gold standard, arena leaderboards struggle to scale and host open models, resulting in open-weights systems making up only 16 of the 92 models on Artificial Analysis as of September 30, 2026. The Open TTS Leaderboard complements human preference by testing objective dimensions: intelligibility via word or character error rates using Qwen3 ASR, batched speed via inverse real-time factor (RTFx), and speaker similarity (SIM) using WavLM embeddings. This objective approach lowers model evaluation duration from weeks to hours.
Multilingual Support and Voice Cloning Capabilities
The leaderboard benchmarks macro-average WER across English splits from Seed TTS Eval and CV3 Eval, where hexgrad/Kokoro-82M, Supertone/supertonic-3, and fishaudio/s2-pro lead. To account for non-English performance, users can filter by multiple languages, applying character error rate (CER) metrics for Chinese, Japanese, and Korean. Enabling the voice cloning filter displays speaker similarity scores and tradeoffs, highlighting models such as k2-fsa/OmniVoice and FunAudioLLM/Fun-CosyVoice3-0.5B-2512.
Streaming Latency Benchmarks and Interactive Listening
A dedicated Streaming tab evaluates interactive latency by measuring median time-to-first-audio (TTFA) across English prompts from CV3-Eval at batch size 1 on H200 GPUs and CPUs, highlighting systems like kyutai/pocket-tts. Additionally, the Listen tab lets users inspect and vote on model audio outputs directly to bridge objective metrics with human perception, alongside plans to open-source the underlying evaluation scripts.
Saved original article
TLDR 👉 new
TTS leaderboard
focused on open-source and multilingual
The pace of open-source text-to-speech (TTS) model releases has been incredible. On the Hugging Face Hub (as of Sep 30, 2026) there are more than
8K TTS models
available 🚀
Evaluation, however, hasn't kept pace: it remains fragmented and unstandardized.
The gold standard is human preference scores such as MOS or MUSHRA (more on
metrics
). To this end, several arena-based leaderboards have established themselves as useful reference points for the community:
TTS Arena v2
Artificial Analysis
Voice Arena
These arenas compare models by presenting users with TTS outputs from two models, and asking them to choose one over the other. After collecting a sufficient number of votes, an
Elo score
is computed to rank models, typically with the Bradley–Terry model (see
Voice Arena methodology
).
While human preference is the ultimate decider,
arenas cannot scale to keep up with the pace of TTS releases
. This may partly explain why open-source models are underrepresented on arena-style leaderboards: as of Sep 30, 2026, only 16 of the 92 models on
Artificial Analysis
are open-weights, with a similar skew on
Voice Arena
. This likely reflects practical factors: adding an API model requires little more than an API key, whereas an open model must be hosted and served by the arena operator, and commercial providers have more reason to seek placement than open-source authors. Another limitation with arena-style evaluation is voter consistency: no arena can ensure that the same voters with the same criteria of “better” can consistently evaluate models over time. Even the preferences of a single person change over time (“A man cannot step into the same river twice” as famously said by Heraclitus).
To this end, we've built the
Open TTS Leaderboard
, which uses objective metrics to evaluate models on complementary aspects of performance:
Intelligibility
: word/character error rate (WER and CER) between the prompt and the generated audio's transcript, using
Qwen3 ASR
(top ranking open-source model on the
Open ASR Leaderboard
).
Speed
: inverse real-time factor (RTFx) for batched offline inference on an H200 GPU, and time-to-first-audio (TTFA) for quantifying streaming batch size 1 latency on an H200 GPU and CPU.
Speaker similarity
by computing the cosine similarity (SIM) between
WavLM speaker embeddings
of the generated audio and the reference clip.
By relying on objective metrics
evaluating a model drops from a couple weeks (for collecting votes) to a couple hours
⚡
Importantly, the Open TTS Leaderboard does not replace human preference ranking. ASR-based WER provides a proxy for intelligibility, while speaker similarity estimates voice identity preservation. Neither directly measures naturalness, expressiveness, or listener preference. Nevertheless, they can even inform voting-based leaderboards which models to include in their evaluations.
Our intention with this leaderboard is for it to be
shaped by the community
; we want to hear your feedback so the evaluations stay relevant and insightful. The next few sections give an overview of main features of the Open TTS Leaderboard.
Multilingual + voice cloning evaluation
From the default view of the leaderboard, models are ranked by macro-average WER on the English splits of
Seed TTS Eval
(
paper
) and
CV3 Eval
(zero shot) (
paper
).
hexgrad/Kokoro-82M
,
Supertone/supertonic-3
, and
fishaudio/s2-pro
lead the pack on English WER when averaged on these two splits, while the Pareto plots visualize which models strike a good balance between WER, batched inference (RTFx), and size.
English performance doesn't necessarily translate to other languages. Multiple languages can be toggled to rank models on multilingual performance. Seed TTS Eval only has audio for English and Chinese, so the other languages are simply the score on CV3 Eval (zero shot). Note that Chinese, Japanese, and Korean are character-based languages and so character error rate (CER) is reported, and the “Average WER” across languages is a macro-average across languages.
k2-fsa/OmniVoice
,
fishaudio/s2-pro
, and
FunAudioLLM/Fun-CosyVoice3-0.5B-2512
are strong multilingual models.
By toggling “Voice cloning”, the models that support this functionality (on the selected languages) can be compared.
Moreover, a SIM column for speaker similarity now appears in the table, as well as two more Pareto plots for visualizing the tradeoff between SIM, batched inference, and size.
The average WER of some models, such as
bosonai/higgs-tts-3-4b
and
openbmb/VoxCPM2
, improve under voice cloning, namely when a reference audio is provided.
Compare and vote on TTS outputs
Numbers only tell part of the story, and as mentioned earlier
human preference is the ultimate decider
. From the “Listen” tab, you can compare the generated outputs that are behind the metrics, to find which model(s) you prefer!
Pick the
language/dataset
you're interested in, whether you want to compare
voice cloning
, and optionally pick the models or listen to outputs from a random selection.
The “Listen” tab fills an important gap in existing TTS leaderboards: a space to explore model outputs of various models.
You can even give feedback on the generated outputs. As we collect more votes from the community, we may include this data on the leaderboard.
So vote! But please login with your HF account to help us weed out spam/bots.
Streaming performance
The “Streaming” tab compares the streaming capabilities. Models are ranked by TTFA (time-to-first-audio), which quantifies how long a user waits after probing a model in order to obtain audio that can be played. This is important for voice agents and other interactive apps.
For streaming models (✅ under “Streaming API”) it's the time until the first audio chunk arrives. For non-streaming models, it's the time until the whole utterance is generated, because playback can't start any earlier. Every model runs one audio at a time (batch size 1), on the same 50 English prompts from CV3-Eval, on the same hardware and in its default voice. We drop the first 3 runs as warm-up and report the median TTFA across the rest.
The default view compares performance on an H200 GPU. Results are also available for CPU for a small (but growing) set of models!
kyutai/pocket-tts
is a great model for streaming on both GPU and CPU!
Conclusion
The goal of the Open TTS Leaderboard is not only to keep up with the incredible pace of TTS model releases, but to be shaped by the community; we want to hear your feedback so the evaluations stay relevant and insightful. Let us know which datasets, models, and metrics you want to see!
For now, we've focused on:
Open-source models
, to put forward many great models that have been neglected by arena-style evaluations.
Multilingual
, since English performance is not a suitable proxy for other languages.
We will soon open-source the evaluation scripts, much like the Open ASR Leaderboard
repo
, so that you can directly provide your feedback and suggestions via GitHub Issues and PRs! Let's shape TTS evaluations together 🤗