How to Create an SRT File for Video Subtitles

What an SRT file is and why you need one

An SRT file is a plain text document that holds subtitles for video. It contains three pieces of information for each subtitle: a sequence number, the time when the subtitle appears and disappears, and the text itself. Video players like VLC, Windows Media Player, and most online platforms read SRT files and display the subtitles over your video at the right moments.

You create an SRT file when you want to add subtitles to a video you own or have made. The file sits separately from the video itself — you don't embed it into the video file. Instead, you load both the video and the SRT file into a player, and they sync together. This approach lets you edit subtitles without re-encoding the video, and it works across almost every platform.

Key Takeaways

An SRT file is a text document with three parts per subtitle: a number, a time range, and the words to display.
You can write an SRT file in any text editor — Notepad, Word, or a dedicated subtitle tool — as long as you save it as plain text with the .srt extension.
The timing format is hours:minutes:seconds,milliseconds, and you must use a comma before milliseconds, not a period.
Most video players will automatically find and display an SRT file if it has the same name as your video file and sits in the same folder.

The structure of an SRT file

Every subtitle in an SRT file follows the same pattern. The first line is a number — starting at 1 for the first subtitle, 2 for the second, and so on. The second line is the time range: when the subtitle starts and when it ends, separated by an arrow made of two hyphens and a greater-than sign (-->). The third line (or lines, if the subtitle is long) is the text you want to display. A blank line separates each subtitle from the next.

Here is what a real SRT file looks like:

1 00:00:05,000 --> 00:00:10,000 Welcome to the video. 2 00:00:10,500 --> 00:00:15,000 This is the second subtitle. 3 00:00:15,500 --> 00:00:20,000 You can have multiple lines in a single subtitle if needed.

The timing uses hours, minutes, seconds, and milliseconds. Always use a comma before the milliseconds, not a period. If your subtitle starts at 5 seconds and 0 milliseconds, write 00:00:05,000. If it starts at 1 minute, 30 seconds, and 500 milliseconds, write 00:01:30,500.

Creating an SRT file in a text editor

Open Notepad (on Windows), TextEdit (on Mac), or any plain text editor. Type your subtitles in the format described above: number, time range, text, blank line, repeat. Do not use Word or Google Docs unless you save the file as plain text, because those programs add invisible formatting that will break the SRT file.

Once you have typed all your subtitles, go to File and choose Save As. Name the file with the same name as your video — if your video is called my_video.mp4, name the file my_video.srt. The extension must be .srt, not .txt. Save it in the same folder as your video file. When you open the video in a player that supports SRT files, the subtitles should appear automatically.

If the subtitles do not appear, check three things: the file name matches the video name exactly (except for the extension), both files are in the same folder, and your video player supports external subtitle files. VLC supports them. Windows Media Player supports them. Most online video platforms do not — you would need to upload the SRT file separately through their subtitle interface.

Using a dedicated subtitle editor

If you are working with a long video or need to sync subtitles precisely, a dedicated subtitle editor is faster than typing in Notepad. Subtitle Edit is free and runs on Windows. Aegisub is free and runs on Windows, Mac, and Linux. Both let you play the video, click at the moment a subtitle should start and stop, and type the text — the timing is filled in automatically.

These tools also let you adjust timing after you have created the subtitles. If a subtitle appears a half-second too early, you can shift it without retyping. They can also import subtitles from other formats and export to SRT, which is useful if you are converting subtitles from another language or source.

Download Subtitle Edit from nikse.dk/SubtitleEdit or Aegisub from aegisub.org. Both are open-source and do not cost money. Install the program, open your video file, and the editor will walk you through creating subtitles with the video playing alongside.

Timing your subtitles correctly

The most common mistake is getting the timing wrong. A subtitle that appears too early or too late will confuse viewers. The best way to time subtitles is to watch the video and note the exact moment each line of dialogue starts and ends. If you are using a text editor, you may need to play the video in a separate window and pause it to read the time.

Most video players show the current time in the bottom left or bottom right corner. Pause the video at the moment a subtitle should start, read the time, and write it down. Pause again when the subtitle should end. If your video player does not show milliseconds, estimate them — 500 milliseconds is halfway through a second. A subtitle that starts at 5 seconds and 250 milliseconds would be 00:00:05,250.

If you are working with a long video, a subtitle editor saves time because it plays the video inside the editor and lets you click to set start and end times. You do not have to switch between windows or write times down by hand.

Uploading subtitles to online platforms

YouTube, Vimeo, and other video platforms do not automatically read SRT files from your computer. Instead, you upload the SRT file through the platform's subtitle interface. On YouTube, go to your video, click Details, scroll to Subtitles, and choose Add Language. You can then upload your SRT file or paste the text directly.

Vimeo has a similar process: go to your video settings, find Subtitles, and upload the file. Other platforms vary, but most have a subtitle or caption section in the video settings where you can upload an SRT file. Check the platform's help documentation if you cannot find the subtitle upload option.

Once you upload an SRT file to an online platform, the platform may convert it to its own format or store it separately. You keep the original SRT file on your computer for your own use and for uploading to other platforms.

Common mistakes and how to fix them

The most common mistakes are a missing blank line between subtitles, a period instead of a comma before milliseconds, and a mismatch between the file name and the video name. If your SRT file does not load, open it in a text editor and check the format. Each subtitle should have a blank line after it. The time format should be 00:00:00,000 --> 00:00:05,000, not 00:00:00.000.

If the file name does not match the video, rename the SRT file to match. If your video is interview.mp4, the SRT file must be interview.srt. Capitalization usually does not matter, but the extension must be exactly .srt.

Another common issue is saving the file as .txt instead of .srt. If you saved it as my_video.txt, rename it to my_video.srt. On Windows, you may need to turn on the option to show file extensions before you can rename the extension. On Mac, right-click the file, choose Get Info, and change the name in the Name field.

Frequently Asked Questions

Can I use Microsoft Word to create an SRT file?

You can type the subtitles in Word, but you must save the file as plain text. Go to File, Save As, and choose Plain Text (.txt) from the dropdown. Then rename the file from .txt to .srt. Do not save it as a Word document (.docx), because the hidden formatting will break the SRT file.

What if my subtitles are out of sync with the video?

Open the SRT file in a text editor and adjust the times. If every subtitle is 2 seconds too early, add 2 seconds to every start and end time. If only some subtitles are off, adjust those individual lines. After you save the file, reload the video in your player to see the changes.

Can I have multiple lines of text in one subtitle?

Yes. Type as many lines as you need before the blank line that separates subtitles. Most players display up to two or three lines comfortably, so keep each subtitle short. If a line is longer than 42 characters, break it into two lines within the same subtitle.

Do I need to embed the SRT file into the video?

No. The SRT file stays separate from the video. The video player reads both files at the same time and displays the subtitles over the video. This is why the file name must match — the player looks for an SRT file with the same name as the video.

What video formats work with SRT files?

SRT files work with any video format — MP4, AVI, MKV, MOV, and others. The format of the video does not matter. What matters is whether your video player supports external subtitle files. VLC supports all formats. Windows Media Player supports most. Check your player's documentation if subtitles do not load.

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