YouTube Subtitles: How to Make Them and Sync Them

There are three routes to making subtitles for YouTube in YouTube Studio: upload a file with the text and its timings (for example, an .srt), provide the transcript so that YouTube syncs it with the video, or type them as you play it. Automatic captions are a starting point, but YouTube asks you to always review them.

The three ways to add subtitles

Subtitles are added from YouTube Studio: in the left-hand menu you choose “Subtitles”, select the video, add the language and, under “Subtitles”, click “Add”. You can also add subtitles during the upload process. Then you choose one of these options:

Option	What you provide	When it fits
Upload a file	A file with the text and the timestamps of each line, such as an .srt.	When you already have the synced text, because your editing software or production tool prepared it.
Auto-sync	You enter the video's text or upload a transcript file, and YouTube syncs it with the video.	When you have the script or a faithful transcript of what is said.
Type manually	You play the video and enter the subtitles; you can pause it while you type.	Short videos or one-off fixes.
Automatic captions	Nothing: YouTube uses speech recognition technology to create them.	As a draft that you review and correct.

Auto-sync has conditions: the transcript must be in a language supported by YouTube's speech recognition and in the same language that is spoken in the video, and YouTube does not recommend it for videos longer than an hour or with low audio quality. If you type them by hand, include the sounds that matter, such as [APPLAUSE] or [THUNDER], so that viewers know what is happening in the video.

Inside an .srt file

A subtitle file contains the text of what is said in a video and the timecodes that indicate when that text should be shown. YouTube supports many formats, but if you have never created one it recommends SubRip (.srt) or SubViewer (.sbv): you only have to enter the basic timing information and you can edit them with any plain text editor. The main difference between the two is the format of the subtitles' start and end times.

Here is a block from an .srt file of the kind the Estudio de Canales prepares:

12
00:01:04,250 --> 00:01:07,900
The first stop is only two streets away,
next to the old station.

• A sequence number for each subtitle.
• The start and end time, in hours, minutes, seconds and milliseconds after a comma, separated by an arrow, just like in the SubRip example in YouTube's help.
• The text, on one or two lines.
• A blank line before the next block.

Three details keep the file from looking wrong: only basic .srt versions are supported, style information (tags) is not recognised, and the file must be set to UTF-8 with no formatting. If what you are saving is a transcript in a language other than English, YouTube also recommends UTF-8 encoding to improve display accuracy.

Subtitling with AI: automatic captions and transcription

When people talk about AI for subtitling videos, the first thing you have to hand is YouTube's own automatic captions. If automatic captions are available, they are published automatically on the video, in its default language. YouTube's help makes their limits clear:

• They are generated with machine learning algorithms, so quality can vary from one video to another.
• They may not match what is said because of poor pronunciation, accents, dialects or background noise. You should always review them and correct the parts that were not transcribed correctly.
• They may not be ready at the moment you upload the video: the processing time depends on the complexity of the audio.
• Sometimes they are not generated: for example, if they are not available in the video's language, if the sound quality is poor, if there is a long period of silence at the start or if several people's speech overlaps.

YouTube encourages including professional subtitles first. The other route with AI is to use a tool to transcribe the video and give that text to auto-sync. Whatever the tool, treat the transcript as a draft and correct it before uploading it: a transcription error ends up as an error on screen.

If you prepare the transcript file yourself, YouTube's help gives three guidelines: use a blank line to force the start of a new subtitle, use square brackets to indicate background sounds, such as [music] or [laughter], and add >> to identify the person speaking. Transcripts are most useful for videos shorter than an hour that have good sound quality and clear speech, and they must be in the same language as the video.

How to check the sync

Subtitles with the right text but out of sync are almost as annoying as ones with errors. Before calling the video finished:

1. Watch it all the way through with subtitles on and pay attention to scene changes and long pauses: that is where any offset shows.
2. Check proper names, figures and technical terms letter by letter.
3. If you trimmed the video after making the subtitles, redo them: the timings of everything after the cut are shifted.
4. Split long sentences: two short subtitles are better than one there is no time to read.
5. If you see odd characters in accented letters or the ñ, check that the file is saved in UTF-8.
6. If you start from the automatic ones, correct them in YouTube Studio: under “Subtitles”, click “More” next to the subtitles you want to edit, and change or delete the parts that were not transcribed correctly.

Subtitles are one piece of publishing. The rest of the list (title, thumbnail, chapters and AI disclosure) is in the checklist for publishing a YouTube video, and the title, description and tags in SEO for YouTube videos.

How the Estudio de Canales produces subtitles

In the Estudio de Canales subtitles are not transcribed: they are written from what is already known to be in the video.

• The text is the approved script. The scenes' narration is, word for word, the approved script, and the subtitles come from that narration.
• The timings come from the real audio. When a scene's voice arrives, its length becomes that of the audio file, not the word-based estimate. Within each scene, that time is divided among its subtitles by characters.
• Short lines. Each subtitle has at most two lines, which are broken at around 42 characters.
• An .srt in UTF-8. It goes inside the package to upload, as subtitulos.srt, and can also be downloaded separately.
• Checked before the package. Among the “ready to publish” checks, the subtitles one requires that all scenes have narration.

Two limits worth knowing. The studio does not transcribe the audio: if you record your own voice and change the text as you record, the subtitles will still say what the scene says, so review them (there are recording tips in AI voice-over or your own voice). And since each scene's time is divided by characters, a long pause in the middle of a scene can bring a line forward or push it back: check them in YouTube Studio before publishing. You do the upload: the studio prepares the package to upload by hand and does not publish on its own.

Sources consulted

Checked on 9 October 2026. We link to the original source so that you can consult the current text.

• Añadir subtítulos. Google · Ayuda de YouTube.
• Archivos de subtítulos y subtítulos opcionales compatibles. Google · Ayuda de YouTube.
• Consejos para crear un archivo de transcripción. Google · Ayuda de YouTube.
• Utilizar los subtítulos automáticos. Google · Ayuda de YouTube.