WebFaz Subtitles

Sync subtitles

PT

Local by default. Only if you turn on AI is o texto das falas, somente ao clicar em Traduzir legenda sent to Groq. Learn more

Sync subtitles: delay or advance all the lines

If the subtitles appear before or after the speech, enter how many seconds to delay or advance and download the corrected file. The same offset applies to all the lines. The conversion happens in the browser, without sending the file.

Open or drag a subtitle, ZIP or videoSubtitles up to 5 MB · ZIP up to 256 MB · MP4/MOV and MKV/WebM up to 2 GB

Files stay on your device.

Input

JSON: array of objects with start and end in seconds and text with the line. TXT and Markdown: each non-empty line becomes a block.

Output

Adjust timing for conversion

Continue in the video editor or the text editor.

How to do it, step by step

  1. Open or drag the subtitle file.
  2. In the Adjust timing tab, enter the Time adjustment in seconds (positive delays; negative advances).
  3. Check the times in the Output box.
  4. Download the file.

See where to click, with an image of the tool →

When this is useful

Fix subtitles that are early or late

Set a fixed offset for all the lines.

Fit subtitles from another version of the video

A version with a longer intro calls for a delay.

Tips for a good result

  • In the test, an adjustment of +2.5 s moved the line from 00:00:01,000 to 00:00:03,500.
  • It accepts tenths of a second, such as 0.5.

What this tool does not do

  • A single value is applied to all the lines: if the difference grows along the video (for example, from a speed difference), a fixed adjustment does not solve it.
  • If the adjustment leaves any line before 00:00:00, the app refuses and asks you to reduce the offset.
  • Subtitle files of up to 5 MB; ZIP of up to 256 MB; video of up to 2 GB.
  • Everything happens in the browser: the file is not sent. The only exception is the optional translation, which sends only the text of the lines.

Frequently asked questions

Does positive delay or advance?
Positive delays the subtitles; negative advances them.
Can I sync while watching the video?
Yes: in the review tab, open the video in the player and adjust the times of the lines. See the subtitle correction with video page.

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Text written by Marcelo Amantino · updated October 18, 2026 · who we are