Is my subtitle file uploaded anywhere?

No. Your subtitle file is read and adjusted directly in your browser. It is not uploaded to Stay Local Tools servers for processing.

Do I need to understand the math behind this?

No. Just enter two example subtitles — the current time shown in the file, and the correct time it should show at — for a point near the start and a point near the end. This tool works out the rest.

What if I enter the same current time for both points?

This tool needs two different current times to work out how timing changes over the video, so it will ask you to choose two different reference points.

How is this different from FPS Sync?

FPS Sync uses a known frame-rate pair, like 25 fps to 23.976 fps. Two-Point Sync works from two real examples in your file instead, so it also works when you do not know the frame rates involved.

Two-Point Subtitle Sync

Fix subtitles using two reference points, for timing that drifts more over time.

Local Processing

Files stay on your device.

Choose File

or drag and drop files here

Supported: .srt, .smi, .sami, .vtt

Files stay on your device

Private by design

Your files are processed directly in your browser. They are not uploaded to Stay Local Tools servers for processing. Because the work happens on your device, your files stay with you unless you download or share them yourself.

Note: the website itself still loads normal web files, and may use analytics or ads later. The promise here is about the files and text you put into these tools.

How to Use

Choose your subtitle file (SRT, SMI or VTT).
Find a subtitle near the start and enter its current and correct time as Point 1.
Find a subtitle near the end and enter its current and correct time as Point 2.
Click Apply Sync.
Download the synced file.

When a fixed delay is not enough

A fixed delay works when every subtitle is off by the same amount. But sometimes subtitles start almost in sync and drift further apart the longer the video runs — a common sign of a frame-rate mismatch that does not match a standard preset, or a subtitle edited from a different video release.

How two-point sync works

You give this tool two examples: a subtitle near the start, and one near the end, each with its current (wrong) time and the correct time it should show at. From those two points, the tool works out how to stretch or shift every other subtitle so both points — and everything between them — line up correctly.

Picking good reference points

Choose two points as far apart as possible, ideally one near the very start and one near the very end of the video. Points that are close together make the fix less accurate, since small timing mistakes get stretched across the whole file.

Questions and Answers

: No. Your subtitle file is read and adjusted directly in your browser. It is not uploaded to Stay Local Tools servers for processing.
: No. Just enter two example subtitles — the current time shown in the file, and the correct time it should show at — for a point near the start and a point near the end. This tool works out the rest.
: This tool needs two different current times to work out how timing changes over the video, so it will ask you to choose two different reference points.
: FPS Sync uses a known frame-rate pair, like 25 fps to 23.976 fps. Two-Point Sync works from two real examples in your file instead, so it also works when you do not know the frame rates involved.

Other Languages

Español

Sincronización progresiva de subtítulos

Corrige subtítulos que se desincronizan progresivamente usando dos puntos de referencia. El archivo se procesa directamente en tu navegador y no se sube a los servidores de Stay Local Tools para el procesamiento.

Preguntas frecuentes

: No. Tu archivo de subtítulos se lee y se ajusta directamente en tu navegador; no se sube a los servidores de Stay Local Tools.
: No. Solo indica dos ejemplos: el tiempo actual del subtítulo y el tiempo correcto, para un punto cerca del inicio y otro cerca del final. Esta herramienta calcula el resto.
: Esta herramienta necesita dos tiempos actuales distintos para calcular cómo cambia la sincronización, así que te pedirá elegir dos puntos diferentes.

Português (Brasil)

Sincronização progressiva de legendas

Corrija legendas que se desincronizam progressivamente usando dois pontos de referência. O arquivo é processado diretamente no navegador e não é enviado aos servidores do Stay Local Tools para processamento.

Perguntas frequentes

: Não. Seu arquivo de legenda é lido e ajustado diretamente no navegador; ele não é enviado aos servidores do Stay Local Tools.
: Não. Basta informar dois exemplos: o tempo atual da legenda e o tempo correto, para um ponto perto do início e outro perto do fim. Esta ferramenta calcula o resto.
: Esta ferramenta precisa de dois tempos atuais diferentes para calcular como a sincronização muda, então ela vai pedir para você escolher dois pontos diferentes.

한국어

자막 싱크 점점 밀림 보정

두 개의 기준점을 사용해 점점 어긋나는 자막의 싱크를 자동으로 보정할 수 있습니다. 파일은 브라우저에서 직접 처리되며 Stay Local Tools 서버에 업로드되지 않습니다.

자주 묻는 질문

: 아니요. 자막 파일은 브라우저에서 직접 읽고 조정되며 Stay Local Tools 서버에는 업로드되지 않습니다.
: 아니요. 시작 부분과 끝 부분 근처에서 각각 현재 자막 시간과 올바른 시간을 예시로 입력하기만 하면 나머지는 이 도구가 계산합니다.
: 이 도구는 싱크가 어떻게 변하는지 계산하려면 서로 다른 현재 시간 두 개가 필요하므로, 다른 두 지점을 선택하라는 안내가 표시됩니다.