FA-Bench Leaderboard
FA-Bench measures how closely word and phone timestamps land on the boundaries human linguists placed.
ASR with timestamps, word timestamp F1 at 20 ms
| Rank | Range | System | Access | Mean F1 | 95% interval | TIMIT clean | TIMIT noisy | Buckeye clean | Buckeye noisy | WER TIMIT | WER Buckeye | Price, $ per audio hour |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | Google Chirp 2 | Commercial | 0.486 | 0.475โ0.498 | 0.488 | 0.497 | 0.492 | 0.469 | 4.2 | 13.1 | $0.96 |
| 2 | 2โ3 | CrisperWhisper โ | Open | 0.455 | 0.442โ0.466 | 0.484 | 0.472 | 0.463 | 0.399 | 3.6 | 11.5 | โ |
| 3 | 2โ3 | Google Chirp 3 โก | Commercial | 0.452 | 0.442โ0.462 | 0.460 | 0.438 | 0.479 | 0.431 | 5.2 | 13.5 | $0.96 |
| 4 | 4 | Qwen3-ASR-Flash | Commercial | 0.363 | 0.353โ0.374 | 0.398 | 0.355 | 0.376 | 0.322 | 1.8 | 10.1 | $0.13 |
| 5 | 5 | Mistral Voxtral Mini | Commercial | 0.308 | 0.298โ0.319 | 0.315 | 0.294 | 0.325 | 0.299 | 2.4 | 13.4 | $0.18 |
| 6 | 6โ7 | ElevenLabs Scribe v2 | Commercial | 0.281 | 0.275โ0.288 | 0.304 | 0.297 | 0.267 | 0.256 | 2.1 | 10.7 | $0.22 |
| 7 | 6โ7 | Amazon Transcribe | Commercial | 0.273 | 0.263โ0.284 | 0.259 | 0.264 | 0.289 | 0.281 | 2.7 | 10.3 | $0.36 |
| 8 | 8โ9 | AssemblyAI Universal-3.5 Pro | Commercial | 0.213 | 0.204โ0.222 | 0.237 | 0.218 | 0.211 | 0.185 | 2.0 | 9.0 | $0.21 |
| 9 | 8โ9 | TorchAudio (ASR) | Open | 0.209 | 0.203โ0.216 | 0.254 | 0.213 | 0.211 | 0.159 | 10.8 | 27.8 | โ |
| 10 | 10โ11 | Deepgram Nova-3 โก | Commercial | 0.170 | 0.161โ0.178 | 0.191 | 0.185 | 0.155 | 0.148 | 2.4 | 10.8 | $0.26 |
| 11 | 10โ11 | Parakeet-TDT | Open | 0.164 | 0.155โ0.172 | 0.172 | 0.174 | 0.156 | 0.153 | 2.4 | 11.0 | โ |
| 12 | 12 | IBM Watson STT en-US | Commercial | 0.149 | 0.142โ0.157 | 0.135 | 0.132 | 0.176 | 0.155 | 5.1 | 12.4 | $1.27 |
| 13 | 13โ14 | Azure AI Speech | Commercial | 0.100 | 0.094โ0.107 | 0.117 | 0.112 | 0.089 | 0.083 | 3.4 | 11.5 | $1.00 |
| 14 | 13โ14 | Speechmatics Enhanced | Commercial | 0.097 | 0.091โ0.103 | 0.110 | 0.088 | 0.107 | 0.083 | 2.5 | 11.4 | $0.75 |
| 15 | 15โ16 | Whisper large-v3 | Open | 0.049 | 0.046โ0.052 | 0.029 | 0.029 | 0.067 | 0.069 | 2.9 | 13.7 | โ |
| 16 | 15โ16 | Whisper-timestamped | Open | 0.049 | 0.046โ0.052 | 0.021 | 0.022 | 0.075 | 0.076 | 2.5 | 13.4 | โ |
| โ | โ | Olewave Olign v1 | Commercial | 0.681 | 0.673โ0.690 | 0.786 | 0.695 | 0.660 | 0.585 | 2.2 | 10.2 | $0.18 |
โ CrisperWhisper's authors used TIMIT to build its word timing and don't say which TIMIT files. FA-Bench tests on TIMIT's test files, so if the authors used those too, its TIMIT scores come from audio it has already seen.
โก Chirp 3 ends the last word of 15% of clean Buckeye test utterances more than 0.3 s after the audio does.
โก Deepgram ends the last word of 24% of clean Buckeye test utterances more than 0.3 s after the audio does.
Every row is one system as shipped. A cascade of a recognizer and a forced aligner is not ranked here. It shows on the forced alignment boards under Recognized words, and in the F1 Drop of its aligner's row. Olign's price is $0.18 an hour, which is its launch promotion price. Its list price is $0.21.
Google Chirp 2 is chirp_2, Speech-to-Text API v2. Google Chirp 3 is chirp_3, Speech-to-Text API v2. Qwen3-ASR-Flash is qwen3-asr-flash-filetrans, DashScope API v1. Mistral Voxtral Mini is voxtral-mini-2602, API v1. ElevenLabs Scribe v2 is scribe_v2, API v1. Amazon Transcribe is en-US, batch API 2017-10-26. AssemblyAI Universal-3.5 Pro is universal-3-5-pro, API v2. Deepgram Nova-3 is nova-3, build 2025-07-31.0, API v1. IBM Watson STT en-US is en-US large speech model, API v1. Azure AI Speech is en-US, short audio REST API v1. Speechmatics Enhanced is enhanced, builds 16.0.0 and 16.1.0, API v2. Olewave Olign v1 is olign-1.0, Olign API v1.
Olign no longer takes part in FA-Bench. Its last results, from October 2026, are listed unranked at the bottom of the table.
Forced alignment, word timestamp F1 at 20 ms
| Rank | Range | System | Access | Mean F1 | 95% interval | F1 Drop | TIMIT clean | TIMIT noisy | Buckeye clean | Buckeye noisy | MAE TIMIT | MAE Buckeye | Price, $ per audio hour |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | MFA 3.4 | Open | 0.658 | 0.650โ0.667 | 0.030 | 0.685 | 0.649 | 0.706 | 0.594 | 21.8 | 21.3 | โ |
| 2 | 2 | PocketSphinx | Open | 0.648 | 0.639โ0.658 | 0.033 | 0.645 | 0.594 | 0.728 | 0.627 | 30.5 | 22.1 | โ |
| 3 | 3 | NeuFA โ | Open | 0.599 | 0.589โ0.607 | โ | 0.600 | 0.493 | 0.712 | 0.589 | 56.9 | 33.9 | โ |
| 4 | 4 | Charsiu | Open | 0.563 | 0.553โ0.573 | 0.024 | 0.597 | 0.532 | 0.627 | 0.497 | 28.1 | 28.1 | โ |
| 5 | 5 | MAPS โ | Open | 0.547 | 0.537โ0.556 | 0.024 | 0.712 | 0.412 | 0.642 | 0.421 | 25.5 | 37.9 | โ |
| 6 | 6 | CrisperWhisper โ | Open | 0.473 | 0.461โ0.485 | 0.017 | 0.489 | 0.480 | 0.491 | 0.434 | 34.1 | 43.1 | โ |
| 7 | 7 | Meta UnitY2 | Open | 0.439 | 0.428โ0.449 | 0.022 | 0.380 | 0.393 | 0.495 | 0.486 | 52.2 | 40.6 | โ |
| 8 | 8 | Qwen3-FA | Open | 0.402 | 0.391โ0.413 | 0.013 | 0.416 | 0.386 | 0.426 | 0.380 | 32.2 | 33.8 | โ |
| 9 | 9 | Meta MMS-FA | Open | 0.345 | 0.338โ0.352 | 0.014 | 0.353 | 0.350 | 0.344 | 0.332 | 31.1 | 37.1 | โ |
| 10 | 10 | ElevenLabs-FA | Commercial | 0.295 | 0.289โ0.302 | 0.015 | 0.299 | 0.300 | 0.293 | 0.288 | 31.9 | 35.5 | $0.22 |
| 11 | 11โ13 | BFA | Open | 0.272 | 0.264โ0.280 | 0.009 | 0.276 | 0.255 | 0.285 | 0.272 | 51.0 | 57.2 | โ |
| 12 | 11โ13 | WhisperX | Open | 0.271 | 0.264โ0.277 | 0.014 | 0.280 | 0.267 | 0.281 | 0.254 | 37.2 | 41.7 | โ |
| 13 | 12โ13 | TorchAudio | Open | 0.265 | 0.258โ0.272 | 0.013 | 0.273 | 0.255 | 0.275 | 0.256 | 39.8 | 42.4 | โ |
| 14 | 14 | stable-ts | Open | 0.251 | 0.243โ0.260 | 0.015 | 0.197 | 0.210 | 0.301 | 0.297 | 96.8 | 71.2 | โ |
| 15 | 15 | NVIDIA NeMo-FA โ | Open | 0.155 | 0.149โ0.163 | 0.008 | 0.157 | 0.158 | 0.151 | 0.156 | 79.2 | 91.4 | โ |
| โ | โ | Olewave Olign v1 | Commercial | 0.735 | 0.726โ0.743 | โ | 0.805 | 0.710 | 0.755 | 0.668 | 18.2 | 22.4 | $0.18 |
F1 Drop is how far an aligner's mean F1 falls when it is handed the words Qwen3-ASR recognized in place of the reference transcript. MFA 3.4, for example, scores 0.658 on the reference transcript and 0.628 on recognized words, an F1 Drop of 0.030.
โ NeuFA was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
โ MAPS was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
โ CrisperWhisper's authors used TIMIT to build its word timing and don't say which TIMIT files. FA-Bench tests on TIMIT's test files, so if the authors used those too, its TIMIT scores come from audio it has already seen.
โ NeMo-FA here is its 80 ms model. The 40 ms model's mean F1 is 0.199.
The Transcript switch shows each aligner handed the words Qwen3-ASR recognized in place of the reference transcript. Those words have a WER of 2.0% on TIMIT core test and 10.2% on Buckeye test on clean audio. NeuFA was not run on recognized words. MFA 3.4 on Parakeet-TDT's words scores 0.625, and WhisperX on Whisper large-v3's words scores 0.234. Olign's price is $0.18 an hour, which is its launch promotion price. Its list price is $0.21.
NeuFA is trained with its open-source code on GitHub, not released. ElevenLabs-FA is forced-alignment, API v1. Olewave Olign v1 is olign-1.0, Olign API v1.
Olign no longer takes part in FA-Bench. Its last results, from October 2026, are listed unranked at the bottom of the table.
Forced alignment, phone boundary F1 at 20 ms
| Rank | Range | System | Access | Mean F1 | 95% interval | F1 Drop | TIMIT clean | TIMIT noisy | Buckeye clean | Buckeye noisy | PER TIMIT | PER Buckeye | Price, $ per audio hour |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | MFA 3.4 | Open | 0.436 | 0.431โ0.443 | 0.008 | 0.393 | 0.372 | 0.518 | 0.463 | 34.8 | 26.1 | โ |
| 2 | 2 | PocketSphinx | Open | 0.402 | 0.396โ0.408 | 0.007 | 0.338 | 0.326 | 0.494 | 0.450 | 33.9 | 26.0 | โ |
| 3 | 3 | MAPS โ | Open | 0.383 | 0.377โ0.389 | 0.005 | 0.454 | 0.319 | 0.445 | 0.313 | 30.7 | 34.9 | โ |
| 4 | 4 | Charsiu | Open | 0.372 | 0.367โ0.378 | 0.003 | 0.360 | 0.347 | 0.424 | 0.359 | 30.3 | 31.7 | โ |
| 5 | 5 | NeuFA โ | Open | 0.366 | 0.360โ0.371 | โ | 0.326 | 0.277 | 0.460 | 0.399 | 36.0 | 28.0 | โ |
| 6 | 6 | TorchAudio | Open | 0.235 | 0.230โ0.240 | 0.005 | 0.208 | 0.206 | 0.266 | 0.261 | 35.9 | 28.5 | โ |
| 7 | 7 | BFA | Open | 0.217 | 0.212โ0.221 | 0.004 | 0.183 | 0.178 | 0.255 | 0.251 | 36.2 | 32.1 | โ |
| โ | โ | Olewave Olign v1 | Commercial | 0.452 | 0.446โ0.459 | โ | 0.410 | 0.393 | 0.523 | 0.483 | 35.4 | 28.2 | $0.18 |
F1 Drop is how far an aligner's mean F1 falls when it is handed the words Qwen3-ASR recognized in place of the reference transcript. MFA 3.4, for example, scores 0.436 on the reference transcript and 0.428 on recognized words, an F1 Drop of 0.008.
โ MAPS was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
โ NeuFA was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
FALCON is left off this board because it is handed the reference phones, which no other aligner here gets. Its mean F1 is 0.560. The Transcript switch shows each aligner handed the words Qwen3-ASR recognized in place of the reference transcript. Those words have a WER of 2.0% on TIMIT core test and 10.2% on Buckeye test on clean audio. NeuFA was not run on recognized words. MFA 3.4 on Parakeet-TDT's words scores 0.429.
NeuFA is trained with its open-source code on GitHub, not released. Olewave Olign v1 is olign-1.0, Olign API v1.
Olign no longer takes part in FA-Bench. Its last results, from October 2026, are listed unranked at the bottom of the table.
Forced alignment with recognized words, word timestamp F1 at 20 ms
| Rank | Range | System | Access | Mean F1 | 95% interval | F1 Drop | TIMIT clean | TIMIT noisy | Buckeye clean | Buckeye noisy | MAE TIMIT | MAE Buckeye | Price, $ per audio hour |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | MFA 3.4 | Open | 0.628 | 0.619โ0.637 | 0.030 | 0.677 | 0.642 | 0.649 | 0.545 | 21.8 | 22.7 | โ |
| 2 | 2 | PocketSphinx | Open | 0.615 | 0.605โ0.624 | 0.033 | 0.632 | 0.585 | 0.669 | 0.573 | 30.6 | 22.6 | โ |
| 3 | 3 | Charsiu | Open | 0.539 | 0.529โ0.550 | 0.024 | 0.587 | 0.522 | 0.586 | 0.463 | 28.2 | 26.1 | โ |
| 4 | 4 | MAPS โ | Open | 0.523 | 0.514โ0.532 | 0.024 | 0.702 | 0.407 | 0.595 | 0.387 | 25.5 | 39.8 | โ |
| 5 | 5 | CrisperWhisper โ | Open | 0.456 | 0.443โ0.468 | 0.017 | 0.485 | 0.472 | 0.464 | 0.403 | 33.8 | 39.2 | โ |
| 6 | 6 | Meta UnitY2 | Open | 0.417 | 0.406โ0.428 | 0.022 | 0.375 | 0.385 | 0.461 | 0.447 | 52.4 | 39.8 | โ |
| 7 | 7 | Qwen3-FA | Open | 0.389 | 0.377โ0.399 | 0.013 | 0.408 | 0.383 | 0.405 | 0.358 | 32.6 | 30.6 | โ |
| 8 | 8 | Meta MMS-FA | Open | 0.331 | 0.324โ0.337 | 0.014 | 0.349 | 0.346 | 0.323 | 0.305 | 31.1 | 34.3 | โ |
| 9 | 9 | ElevenLabs-FA | Commercial | 0.280 | 0.274โ0.287 | 0.015 | 0.295 | 0.293 | 0.271 | 0.261 | 31.9 | 34.0 | $0.22 |
| 10 | 10โ11 | BFA | Open | 0.263 | 0.255โ0.271 | 0.009 | 0.272 | 0.251 | 0.283 | 0.247 | 51.0 | 48.6 | โ |
| 11 | 10โ12 | WhisperX | Open | 0.257 | 0.250โ0.263 | 0.014 | 0.276 | 0.263 | 0.259 | 0.230 | 37.3 | 39.7 | โ |
| 12 | 11โ12 | TorchAudio | Open | 0.252 | 0.245โ0.260 | 0.013 | 0.269 | 0.252 | 0.254 | 0.234 | 39.9 | 39.8 | โ |
| 13 | 13 | stable-ts | Open | 0.236 | 0.228โ0.244 | 0.015 | 0.193 | 0.204 | 0.278 | 0.270 | 97.8 | 70.8 | โ |
| 14 | 14 | NVIDIA NeMo-FA โ | Open | 0.147 | 0.140โ0.154 | 0.008 | 0.154 | 0.154 | 0.139 | 0.140 | 79.3 | 88.8 | โ |
| โ | โ | Olewave Olign 0.9 | Commercial | 0.704 | 0.694โ0.712 | 0.031 | 0.791 | 0.697 | 0.703 | 0.623 | 18.3 | 20.8 | โ |
F1 Drop is how far an aligner's mean F1 falls when it is handed the words Qwen3-ASR recognized in place of the reference transcript. MFA 3.4, for example, scores 0.658 on the reference transcript and 0.628 on recognized words, an F1 Drop of 0.030.
โ MAPS was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
โ CrisperWhisper's authors used TIMIT to build its word timing and don't say which TIMIT files. FA-Bench tests on TIMIT's test files, so if the authors used those too, its TIMIT scores come from audio it has already seen.
โ NeMo-FA here is its 80 ms model. The 40 ms model's mean F1 is 0.189.
Qwen3-ASR's words have a WER of 2.0% on TIMIT core test and 10.2% on Buckeye test on clean audio. NeuFA was not run on recognized words. Olign v1 was not run on recognized words, so the unranked Olign row here is Olign 0.9.
ElevenLabs-FA is forced-alignment, API v1. Olewave Olign 0.9 is olign-0.9.
Olign no longer takes part in FA-Bench. Its last results, from October 2026, are listed unranked at the bottom of the table.
Forced alignment with recognized words, phone boundary F1 at 20 ms
| Rank | Range | System | Access | Mean F1 | 95% interval | F1 Drop | TIMIT clean | TIMIT noisy | Buckeye clean | Buckeye noisy | PER TIMIT | PER Buckeye | Price, $ per audio hour |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | MFA 3.4 | Open | 0.428 | 0.423โ0.434 | 0.008 | 0.394 | 0.372 | 0.502 | 0.446 | 34.8 | 28.2 | โ |
| 2 | 2 | PocketSphinx | Open | 0.395 | 0.389โ0.401 | 0.007 | 0.337 | 0.325 | 0.482 | 0.436 | 34.0 | 27.2 | โ |
| 3 | 3 | MAPS โ | Open | 0.378 | 0.372โ0.384 | 0.005 | 0.455 | 0.319 | 0.435 | 0.303 | 30.7 | 35.8 | โ |
| 4 | 4 | Charsiu | Open | 0.369 | 0.363โ0.375 | 0.003 | 0.361 | 0.347 | 0.417 | 0.352 | 30.3 | 32.7 | โ |
| 5 | 5 | TorchAudio | Open | 0.230 | 0.226โ0.235 | 0.005 | 0.207 | 0.205 | 0.260 | 0.250 | 35.9 | 30.0 | โ |
| 6 | 6 | BFA | Open | 0.213 | 0.208โ0.217 | 0.004 | 0.183 | 0.177 | 0.253 | 0.238 | 36.2 | 33.6 | โ |
| โ | โ | Olewave Olign 0.9 | Commercial | 0.447 | 0.440โ0.453 | 0.005 | 0.410 | 0.393 | 0.513 | 0.470 | 35.4 | 29.2 | โ |
F1 Drop is how far an aligner's mean F1 falls when it is handed the words Qwen3-ASR recognized in place of the reference transcript. MFA 3.4, for example, scores 0.436 on the reference transcript and 0.428 on recognized words, an F1 Drop of 0.008.
โ MAPS was trained on 7 of the 8 speakers in FA-Bench's Buckeye test set, so most of its Buckeye test audio comes from speakers it was trained on.
Qwen3-ASR's words have a WER of 2.0% on TIMIT core test and 10.2% on Buckeye test on clean audio. NeuFA was not run on recognized words. Olign v1 was not run on recognized words, so the unranked Olign row here is Olign 0.9.
Olewave Olign 0.9 is olign-0.9.
Olign no longer takes part in FA-Bench. Its last results, from October 2026, are listed unranked at the bottom of the table.