Phase 4 · Manual subtitles · No AI

Merge Subtitle Files

Combine two subtitle files and sort their captions by start time.

Work locally

Local text only, up to 1 MiB and 5000 cues. Unsupported VTT styling blocks are refused, not silently lost.

Use the controls above to begin. Files stay on this device.

Results

How to use merge subtitle files

Select a local file if requested, or enter values and review them. Choose Process in browser, review the output and download it before leaving the page. If the browser cannot decode a file, the tool reports the limitation rather than uploading it elsewhere.

Method and accuracy

Overlapping cues remain overlapping. Text is not rewritten or translated. Processing occurs within device and browser limits; actual player compatibility can differ by format. No generated captions, speech transcription or AI enhancements are offered.

Related tools

Manual caption editor · Basic media inspector · Bitrate calculator

How this tool works

Combine two subtitle files and sort their captions by start time.

What to check before sharing

The editor works on basic local subtitle text. It cannot transcribe speech or decode image-based subtitle tracks. Unsupported styling must be rejected rather than silently lost.

No AI or paid processing API. The site does not intentionally upload selected media. See privacy, current format limitations and browser processing explained.