Online Subtitle Shifter

Sync subtitles by shifting SRT & VTT times in milliseconds.
Just drop your file. 100% local processing.

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SRT / VTT Support

Compatible with standard subtitle formats

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Millisecond Precision

Add delays or bring text forward precisely

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100% Local Processing

Your subtitle files are perfectly private

Shift Amount (Milliseconds)

* 1000ms = 1 second. Input a negative value to make subtitles appear earlier.

Original Subtitles (Input SRT/VTT)

Shifted Result (Output)

about,

About the Online Subtitle Shifter

Have you downloaded a movie where the subs are slightly out of sync with the audio? Or do you need to delay every single caption in a VTT file by one second after re-exporting a video? This free online tool instantly solves the problem.

It supports the industry standard .srt (SubRip) and HTML5 .vtt (WebVTT) files. Simply drag & drop your file, choose the amount of milliseconds to delay or advance the subtitles, and shift. Best of all, your text never leaves your browser.

how to use,

How to Use

STEP 1

Import Data

Drag and drop your .srt or .vtt file, or manually paste the text contents.

STEP 2

Set Shift Amount

Input delay in milliseconds. Use positive to delay, negative to bring forward.

STEP 3

Shift & Save

Press "Execute Shift". Copy the result or download it as a new file.

glossary,

Glossary

SRT (SubRip Text): The most widely used subtitle file format. Composed of three elements — sequential number, timestamp, and text — it is broadly supported by video editing software and media players.
VTT (WebVTT): The web-standard subtitle format. Used in combination with the HTML5 <video> tag and optimized for displaying video captions in browsers.
Timestamp: The time information indicating the start and end display time of a subtitle cue. Written in the format "00:01:23,456 --> 00:01:25,789".
Time Shift (Offset): The process of shifting the timing of all subtitles at once forward or backward. When subtitles are out of sync with the video, you can fine-tune them to the millisecond.
Encoding: The method used to represent characters as bytes. UTF-8 is recommended for subtitle files; however, older files may use Shift_JIS or EUC-JP.
Frame Rate: The number of frames per second in a video. Subtitle timing mismatches are often caused by a difference in frame rate between the source video and the subtitle file.
Subtitle Synchronization: Precisely aligning the display timing of subtitle text with the audio and video of a film. This is the primary function of this tool.

faq,

FAQ

Q.Is my uploaded subtitle file saved on a server?: No. All processing — file reading, time adjustment, and download — happens entirely within your browser. Your file is never sent anywhere externally.
Q.What file formats are supported?: SRT (SubRip Text) and VTT (WebVTT) are supported — the two most commonly used formats in video streaming and editing.
Q.What is the minimum adjustment granularity?: Precise time adjustment down to 1 millisecond is possible. Positive values delay subtitles; negative values advance them.
Q.Can I shift only specific subtitle lines?: The current version specializes in shifting all subtitles at once. If you need to adjust only specific lines, manual editing in a text editor is recommended.
Q.Can it handle subtitle files with non-Latin characters?: Yes. UTF-8 encoded files with Japanese, Chinese, Korean, or any other multi-byte characters are handled correctly.
Q.Can it handle large files?: Yes. Because processing happens in browser memory, even subtitle files with thousands of lines are handled quickly without issues.
Q.How do I download the converted file?: After shifting the time, click the "Download" button to download the adjusted subtitle file in its original format.