How to Translate an SRT or VTT Subtitle File (and Keep the Timecodes)

To translate subtitles, translate the subtitle file itself (SRT or VTT) with a tool that changes only the text lines and leaves every number and timecode exactly as it was. Then play the video with the new file and check the few subtitles that became too long to read in time. Pasting the whole file into a general translator is the classic way to end up with broken timecodes and subtitles that drift out of sync.

This guide explains how subtitle files are built, what can go wrong, and how to get a translated file you can upload straight away.

How an SRT file works

An SRT file is plain text. Each subtitle (a "cue") has three parts:

12
00:01:04,250 --> 00:01:07,100
I didn't think you'd come.
Neither did I.

A counter (12)
A timecode: when the subtitle appears and disappears, to the millisecond
One or more lines of text

A blank line separates one cue from the next. Only the text lines should be translated. If a translator touches the counter, rewrites the arrow, changes a comma in the timecode to a full stop, or merges two cues, many video players and upload pages reject the file or show subtitles at the wrong moment.

VTT (WebVTT) files, common on the web, look similar. They start with a WEBVTT header, use a full stop before the milliseconds, and may carry settings after the timecode (such as position or alignment) or simple tags like <i> for italics. Those parts must also survive untouched.

Why generic translators break subtitle files

They treat the timecodes as text. Some translators "localize" the numbers, change separators, or translate the arrow line as if it were a sentence.
They merge or split lines. A translator working on the whole text may join cues into paragraphs, so you end up with fewer subtitles than timecodes.
They lose the blank lines that tell players where one cue ends.
They see each cue in isolation. A sentence split over two cues ("I didn't think" / "you'd come") can come out garbled if each half is translated without the other.

A subtitle-aware translator avoids all four: it reads the cues, translates the text with the surrounding lines as context, and writes the file back in the same structure. DropTranslate's subtitle translator works this way: it keeps every counter and timecode as it was and wraps each translated subtitle into the same number of lines, then gives you back an SRT or VTT file.

Before you translate

Start from the final, synced file. Fix timing problems in the original first. Translation won't fix a subtitle that appears too early.
Save it as UTF-8. Older SRT files are sometimes saved in a legacy encoding, which turns accented letters into strange symbols. Most subtitle editors can re-save as UTF-8.
Remove what you don't want translated, such as speaker labels in a style you'll change, or notes for the editor.
Note names and terms that should stay as they are: character names, product names, places.

After you translate: checking line length and reading speed

Translations are often longer than the original, and a subtitle is only on screen for as long as its timecode allows. Professional subtitlers work with three limits:

Lines per subtitle: most style guides allow at most two lines.
Characters per line: a maximum line length, so the text doesn't cover the picture or get cut off on small screens.
Reading speed: how many characters a viewer can comfortably read per second, so a long subtitle on screen for one second is unreadable even if it fits.

The exact numbers differ between platforms, broadcasters, and audiences (children's content is usually slower, for example). If you're delivering to a platform with a style guide, use its numbers.

To check your translated file:

Play the video with the new subtitles at normal speed and watch for subtitles you can't finish reading.
Shorten, don't squeeze. Good subtitles condense: "I didn't think you'd come" can become "I didn't expect you" without losing meaning. A native speaker can do this quickly.
Check line breaks. Break lines at natural points (not between an article and its noun, for example).
Check names, numbers and on-screen text (signs, captions burned into the video) for consistency with what viewers see.

If your editor shows characters per second, sort by that value and fix the fastest subtitles first.

Burned-in subtitles are a different job

If the subtitles are part of the video picture ("hardcoded"), there's no subtitle file to translate. You'd need to recreate the subtitles from a transcript first, then translate that file. Subtitle files that come with the video, or that you can download or export from your editor, are the ones you can translate directly.

Frequently asked questions

Will the timing stay the same after translation?

With a subtitle-aware translator, yes: the timecodes are copied as they are, and only the text changes. If a translated subtitle is too long to read in its time slot, shorten the text rather than changing the timing, unless you're comfortable re-timing in a subtitle editor.

Can I translate subtitles into a language with a different script?

Yes. Make sure the file is saved as UTF-8 and that your video player or platform supports the script. For right-to-left languages such as Arabic or Hebrew, check punctuation at the ends of lines, which some players display on the wrong side.

Is a machine-translated subtitle file good enough to publish?

For internal videos, social clips and first drafts, it's often a good starting point. For a film, a paid course or broadcast, have a native speaker review it: subtitles are short and context-heavy, so tone and idioms matter. See is machine translation good enough? for simple checks.

Should I translate SRT or VTT?

Whichever your platform asks for. The text and timing are equivalent; VTT adds options like positioning and styling. Translate the format you'll upload so you don't need to convert afterwards.

Summary

Translate the subtitle file, not copied text. Keep timecodes and structure untouched, save as UTF-8, then watch the video once with the new file and shorten the subtitles that go by too fast. For other file types, see how to translate a document.

Drop your SRT or VTT file into DropTranslate and get it back translated, with the same timecodes.