'How to Make an SRT File From Text, Audio or Video'

An SRT file looks fussy until you open one. Then it becomes obvious: it is a plain-text list of subtitles, with a start time and an end time attached to each one.

You can write an SRT file by hand if the video is short. For a recording of any real length, it is usually quicker to generate the first draft from the audio, correct the words and timing, and export the finished file.

This guide covers both methods.

What an SRT file contains

SRT is short for SubRip Subtitle. Each subtitle cue has three parts:

1. A sequence number
2. A start and end time
3. The words displayed on screen

Here is a complete two-cue SRT file:

1
00:00:00,000 --> 00:00:03,200
Welcome back. Today we're making subtitles.

2
00:00:03,200 --> 00:00:07,100
We'll start with the audio, then check the timing.

The blank line between cues matters. The timestamp also uses a comma before milliseconds, not a full stop:

hours:minutes:seconds,milliseconds

YouTube accepts basic SRT files saved as plain UTF-8 text. It does not rely on SRT styling markup, so clean text and accurate timing are more useful than elaborate formatting. You can check the current requirements in YouTube's supported subtitle file guide.

Method 1: make an SRT file manually

Manual creation works well for a short clip, a corrected quote, or a video where you already know the exact lines.

1. Open a plain-text editor

Use Notepad on Windows, TextEdit in plain-text mode on macOS, or a code editor such as VS Code. A word processor can add formatting that does not belong in an SRT file.

2. Type the first cue

Start with 1, add the timing on the next line, then add the subtitle text:

1
00:00:00,000 --> 00:00:04,500
This is the first subtitle.

Play the video and note when the speech starts and stops. Leave a blank line before cue 2.

3. Continue in sequence

Increase the cue number by one each time. The timestamps should move forward, and two cues should not accidentally overlap unless that is intentional.

4. Save it with the .srt extension

Use a descriptive filename such as:

interview-english.srt

Choose UTF-8 encoding. This prevents accented characters, Chinese text and other non-English characters from turning into question marks or broken symbols.

5. Test the file

Import the SRT into the platform where it will be used. Watch the opening minute, jump to the middle, and check the final cue. That quick pass catches most numbering and timing errors.

Method 2: generate an SRT file from audio or video

Typing every line and timing every cue is slow. If you have an MP3, WAV, M4A, MP4, MOV or WebM file, you can create a timed transcript first and export it as SRT.

With the CastToAny SRT generator, the workflow is:

1. Upload the audio or video file, or paste a supported public link.
2. Transcribe the speech into timestamped segments.
3. Correct names, terminology and punctuation in the transcript.
4. Download the result as SRT.

The editing step is worth doing. Automatic transcription can mishear a guest's name, a product name or a sentence spoken over music. It is much easier to fix those problems before the subtitle file reaches a video editor.

If your source is specifically an audio recording, the more detailed audio-to-SRT workflow explains how to prepare the file and check the result.

Can you make an SRT file from plain text?

Yes, but plain text does not contain timing. You still need to decide when each subtitle appears and disappears.

For a short script, play the video and add timestamps manually. For a longer recording, use the matching audio or video to generate timing automatically, then replace or correct the transcript text.

Do not divide a paragraph into arbitrary chunks and guess the timing. The subtitles may look fine in a text editor but drift away from the speaker during playback.

Common SRT problems

The file saves as .srt.txt

Some text editors add .txt automatically. Show file extensions in your operating system, then rename the file so it ends with .srt only.

The captions do not appear

Check the arrow between the timestamps. It should be exactly -->, with a start time on the left and an end time on the right.

Also check that the first cue starts at or after 00:00:00,000. A missing comma, malformed timestamp or non-sequential cue can stop an importer from reading the rest of the file.

Characters look broken

Re-save the file as UTF-8 plain text. Encoding is the first thing to check when names or non-English characters display incorrectly.

The timing slowly drifts

Drift usually means the subtitles were timed against a different edit of the video. A trimmed introduction, inserted advertisement or changed playback rate can move every cue after the edit point.

Generate or retime the subtitles against the final video cut.

The subtitles are hard to read

Shorter cues are usually easier to follow than dense paragraphs. Break at a natural pause, keep related words together, and watch the result at normal speed. If you have to pause the video to finish a cue, it is probably too long or too brief on screen.

Using the finished SRT file

SRT is supported by common video platforms and editors. In Adobe Premiere, for example, you can import an SRT like other media and place it on a caption track. Adobe documents that workflow in its caption import guide.

Keep the corrected transcript as well as the SRT. The transcript is useful for show notes, quotations and search; the SRT is the timed delivery format used by the player or editor.

If you already have the recording, you can generate an editable SRT file and check each timestamp before downloading it.