# kaegi/alass

"Automatic Language-Agnostic Subtitle Synchronization"

Repository: https://github.com/kaegi/alass
Canonical: https://ross.abutalabs.com/products/alass
Language: Rust
License: GPL-3.0
License Family: copyleft
Topics: subtitle, incorrect-subtitles, alignment, tool, api, algorithm
Last push: 2023-12-28T02:07:02+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 3484, "days_push": 980, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1437, forks 73 (observed 2026-08-28T04:04:43.811210+00:00)

## What it is
alass is a Rust command line tool that automatically synchronizes subtitles to movies or reference subtitles. It corrects constant offsets, splits from ad breaks or director's cuts, and different framerates using a fast, language-agnostic alignment algorithm.

## Use cases
- fix subtitles that are out of sync with a movie
- correct subtitle timing after ad breaks or director's cut splits
- resync subtitles with a different framerate
- align a subtitle file to a reference subtitle instead of the video
- batch-fix incorrectly timed downloaded subtitles

## When to choose
- you need automatic, accurate subtitle synchronization without manual offset tweaking
- you want language-agnostic alignment between video audio and subtitle text
- you need to fix splits and framerate mismatches, not just constant offsets

## When to avoid
- you need a GUI subtitle editor for manual adjustments
- you need subtitle formats other than srt, ssa/ass, or idx
- you need an actively developed tool with frequent updates

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: cli, audio-processing, parser
- domain: media, developer-tools
- platform: windows, cli, rust
- tags: subtitles, subtitle-sync, srt, video, language-agnostic, alignment, algorithm, command-line, linux

## Member repositories
- kaegi/alass (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:43.811210+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 2026-08-30T04:36:44.399800+00:00, confidence not recorded.
  - readme: https://github.com/kaegi/alass (fetched 2026-08-28T04:04:43.811210+00:00, sha 93dd34f25beb)
- Data as of 2026-08-30T08:39:29.467469+00:00.