Subtitles make your video watchable on mute, accessible, and searchable — and open it up to new languages. Here's how to add them properly, from transcript to file to on-screen captions, and where a professional pass is worth it.
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Most video is now watched without sound at least some of the time, so subtitles are no longer optional — they keep viewers watching, make content accessible, help SEO, and are the first step to reaching audiences in other languages. Here is how to add them, and how to decide between doing it yourself and having it done professionally.
1. Start with an accurate transcript
Subtitles begin as a transcriptof what's said. Get this right first — errors here follow through into every caption and every translated version.
2. Split and time the subtitles
A transcript isn't a subtitle file. The text is broken into short lines (usually one or two lines of up to ~42 characters) and each is given an in and out timecode so it appears and disappears with the speech.
3. Respect reading speed
The most common mistake is subtitles that flash by too quickly. Aim for around 15–17 characters per second and keep line breaks natural. Our free subtitle reading-speed checkerflags any lines a viewer won't be able to read in time.
4. Export the right file format
SRT is the universal default and works almost everywhere. VTT suits web/HTML5 players and supports styling; STL and TTML are used in broadcast. If you're unsure, choose SRT.
5. Add them to your video: closed vs open captions
Closed captions are the SRT/VTT uploaded alongside the video (as on YouTube), which viewers can switch on or off. Open captions(burn-in) are baked into the picture and can't be turned off — ideal for social feeds that autoplay on mute. See our subtitles vs captions vs SDH guide for which to use.
6. Translate for other languages
To subtitle in another language you translate the file — but fitting each line to the on-screen reading speed rather than translating word-for-word. This is a craft best handled by native linguists; see our subtitling services and subtitling rates.
When to do it professionally
For internal or one-off clips, auto-captions plus a careful edit can be enough. For anything public-facing, accessible (SDH), or translated, professional subtitling pays for itself in accuracy, correct reading speed and broadcast-ready delivery. Send us your videoand we'll return an itemised quote, usually the same working day.