# MontrealCorpusTools/Montreal-Forced-Aligner

Command line utility for forced alignment using Kaldi

Repository: https://github.com/MontrealCorpusTools/Montreal-Forced-Aligner
Canonical: https://ross.abutalabs.com/products/montreal-forced-aligner
Homepage: https://montrealcorpustools.github.io/Montreal-Forced-Aligner/
Language: Python
License: MIT
License Family: permissive
Topics: kaldi, forced-alignment, grapheme-to-phone, pronunciation-dictionary, acoustic-model, python
Last push: 2026-08-20T00:18:52+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 98, longevity 100
- inputs: {"age_days": 3964, "days_push": 14, "days_rel": 14, "gap_med": 23.5, "n_releases_24m": 17}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1872, forks 285 (observed 2026-08-28T04:05:47.026494+00:00)

## What it is
Montreal Forced Aligner is a command line utility for time-aligning orthographic transcriptions and pronunciation dictionary entries to audio recordings, built on the Kaldi ASR toolkit. It ships with pre-trained acoustic models and supports training custom models and grapheme-to-phoneme dictionaries for any language.

## Use cases
- align transcriptions to audio recordings of speech corpora
- generate word and phone-level timestamps for speech data
- train acoustic models for a new language
- generate pronunciation dictionaries with grapheme-to-phoneme conversion
- segment long recordings into utterances for phonetic analysis

## When to choose
- you need accurate word/phone-level alignment for phonetic or linguistic research
- you have a pronunciation dictionary and transcribed audio in any language
- you want a scriptable CLI with pre-trained models instead of building Kaldi pipelines yourself

## When to avoid
- you need real-time streaming speech recognition rather than offline alignment
- you have no transcriptions or pronunciation dictionary for your audio
- you need a GUI-based annotation tool

## Facets
- artifact type: cli-tool
- maturity: active
- function: speech-recognition, nlp, cli, machine-learning
- domain: speech-processing, developer-tools
- platform: windows, python, cli
- tags: forced-alignment, kaldi, g2p, phonetics, acoustic-models, pronunciation-dictionaries, speech-corpora, natural-language-processing, linux, macos

## Member repositories
- MontrealCorpusTools/Montreal-Forced-Aligner (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:47.026494+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:14:56.035227+00:00, confidence not recorded.
  - readme: https://github.com/MontrealCorpusTools/Montreal-Forced-Aligner (fetched 2026-08-28T04:05:47.026494+00:00, sha 8dda269eebc1)
  - homepage: https://montrealcorpustools.github.io/Montreal-Forced-Aligner/ (fetched 2026-08-29T10:53:54.292494+00:00, sha dff8b6cf7e14)
  - registry_pypi: https://pypi.org/pypi/montreal-forced-aligner/json (fetched 2026-08-29T10:53:54.301979+00:00, sha fe9cbc8db43b)
- Data as of 2026-08-30T08:39:29.467469+00:00.