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Merge Subtitles

Combine two subtitle files into one bilingual subtitle, with both languages on screen together.

More tools
Subtitle formatsSRT to TextASS to SRTVTT to SRTSRT to VTTSBV to SRTLRC to SRTDFXP to SRTSMI to SRT

or drop files here

Accepts SRT, VTT, ASS

Encrypted upload. Files are deleted automatically after 1 hour.

About Merge Subtitles

Merge Subtitles makes a bilingual subtitle from two single-language files: English with Chinese for language learning, the original dialogue under a translation, or two languages for a family that watches together. Upload two SRT, VTT or ASS files, in any mix, and choose which one goes on top.

Lines are paired by timing, not by number, so files from different sources still line up: each line of the second language joins the line it overlaps most, and lines without a partner stay on their own. Save as SRT for the widest support, or as ASS with two styles, so the second language appears smaller beneath the first, each in a font that suits it.

How to use Merge Subtitles

  1. 1
    Add both subtitle files

    Choose or drop two .srt, .vtt or .ass files; the first card on the page is the first file.

  2. 2
    Choose layout and format

    Under On screen pick which file goes on top, and under Save as choose SRT or ASS (two styles).

  3. 3
    Click Merge Subtitles

    Lines are matched by timing and written into one bilingual file on our server.

  4. 4
    Download and play

    Load the new file with your video; it's named after the first file with _bilingual added.

Why use Cubfile for this

  • Paired by timing

    Lines match on overlapping time, so files with different line splits still combine cleanly.

  • You pick the top language

    First file on top or Second file on top, switched with a single setting.

  • Two styles in ASS

    The second language is set smaller under the first, each with its own font, sized for 1080p.

  • Mixed formats welcome

    Combine an SRT with a VTT or an ASS; encodings are detected per file.

FAQ

Merge Subtitles: questions and answers

How does Merge Subtitles line up two files?
By time. Each line of the bottom file is attached to the top-file line it overlaps most, if they overlap enough. Lines that don't match anything are kept as separate subtitles at their own times. If one file runs consistently early or late, shift its timing before merging so the lines overlap.
Should I merge subtitles into SRT or ASS?
SRT plays almost everywhere and shows the two languages as two lines. ASS gives each language its own style, so the second line is smaller and easier to tell apart, but some TVs and apps don't support ASS.
Can I merge subtitles in different formats?
Yes. Any mix of SRT, VTT and ASS works, and each file's encoding is detected separately, so a GBK Chinese file and a UTF-8 English file combine without garbling. Subtitles in other formats, such as SBV, DFXP or SMI, can be converted to SRT first with the subtitle converters.
Is it free?
Yes. A merge counts as one task: visitors get 2 in total and free accounts 2 a day. VIP has no task limit.
Are my subtitle files stored?
Only for an hour. Both files are uploaded over HTTPS, merged in an isolated process and deleted automatically afterwards.
Share Merge Subtitles with a friendIt runs in any browser, and they can try it without signing up.

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ASSSRT ASS to SRTConvert ASS/SSA subtitles to SRT, styling tags cleaned.
DFXPSRT DFXP to SRTConvert DFXP/TTML captions to SRT.
LRCSRT LRC to SRTTurn LRC lyrics into SRT subtitles, and back.
SBVSRT SBV to SRTConvert YouTube SBV captions to SRT.
SRT Subtitle EditorWatch your video and type, time and fix subtitles line by line.
SRT Shift SubtitlesMove subtitles earlier or later, or fix drift between two points.
UTFSRT Fix Garbled SubtitlesDetect the encoding of garbled subtitles and save them as UTF-8.