How to Translate Subtitles and Check the Result

Fix the source language before translating

Translation carries errors forward. A mistyped product name becomes a mistyped product name in a second language, and a missing line simply disappears from the translation. Proofread the original captions first, then translate, then check the result. One pass over the source saves two over the translation.

Keep the timing and change only the text

A subtitle file binds every line to a start and end time. Translation should not move those times: each translated line has to land on the same frames as the line it replaces. If you retime and translate in the same step, you can no longer tell which of the two made a subtitle appear late.

Where automatic translation fails

Three failures are predictable:

• Proper nouns are translated as if they were ordinary words, so a product name comes back renamed.
• Idioms are rendered literally and stop making sense in the new language.
• Lines grow long enough that they cannot be read in the time available.

All three are catchable in a single review pass if you read the translation against the picture instead of against the original text.

Read the translation against the picture

Reading the two texts side by side only tells you whether the translation is faithful. Reading the new text while the video plays tells you whether it works. Watch for lines that arrive late, sentences that break onto the wrong shot, and subtitles sitting over a bright part of the picture where they cannot be read. Fix the wording first, then the line breaks, then the timing: each change moves the others.

Deliver in the format the player expects

SRT is the safest general choice, VTT is the standard for web playback, and ASS is only worth using when the target player supports its styling. Exporting the wrong format produces a file that opens but shows nothing, which is the most common avoidable mistake in a subtitle delivery.

Common mistakes

• Translating before the source captions have been proofread.
• Retiming and translating in the same pass, so the cause of a late line is unknown.
• Judging the translation against the original text only, without watching the picture.
• Delivering a format the target player cannot read.
• Overwriting the only copy of the source subtitle file.

Frequently asked questions

What is the difference between subtitles and captions?

Captions render dialogue for viewers who cannot hear it, in the original language. Subtitles usually mean the same dialogue translated for a different audience.

Can I translate subtitles automatically?

Automatically, yes, but expect to review the output. Names, idioms and long lines are where automatic translation most often needs correction.

Do I need to re-edit the video after translating subtitles?

No. A translated subtitle file is delivered alongside the same edit, so the picture does not need to be touched.

Which subtitle format should I deliver?

SRT when you do not know the player, VTT for web playback, ASS only when styling is supported and required.

Why are some translated lines too long to read?

Translated text is often longer than the source. Split the line or shorten the wording so it fits the time available, instead of letting one subtitle run while the next one arrives.

Where Aixcut fits

Aixcut translates subtitles in a desktop Chrome or Edge workspace, from a subtitle file the project already holds, and keeps each line’s start and end time in place. Exports are watermark-free, and exporting itself does not consume credits; transcription and translation tasks follow the current credit rules. For the translation task see the subtitle translator; to produce the first version of the captions, start with the subtitle generator.

Official sources

The description of subtitle formats follows the specification pages published by the W3C and the WHATWG, checked in October 2026:

Each line comes from the specification’s own page, checked in October 2026. Formats and player support change; the current specification always governs.