Watching videos with the sound off is more common than you may think. One survey found 92% of viewers watch mobile videos with the sound muted, and half prefer it that way. What’s more, 80% are more likely to finish a video that includes subtitles.
Subtitles can be created with a SubRip subtitle File (SRT)—a text format that synchronizes dialogue with on-screen action. This makes video content more universally accessible and accommodates viewer preferences.
Here’s what SRT is, how to add and edit SRT files, and why it makes videos more inclusive, engaging, and SEO-friendly.
What is an SRT file?
SubRip subtitle file (SRT) is a plain text file format designed to display subtitles or closed captions on a video, with exact start and end timecodes for each sequence of caption text to help synchronize subtitles with the video.
Although there are other subtitle formats, SRT files are among the most widely supported, because they’re easy to edit using any text editor, thanks to their straightforward structure (numbered subtitle blocks with timestamps and text).
Other subtitle file formats
While SRT is a very popular format, it's not the only option. Other subtitle file formats include:
- Web Video Text Tracks Format (WebVTT). A plain text format for displaying timed captions and subtitles along with HTML5 <video> and <audio> elements on web pages. WebVTT files offer more advanced styling and metadata capabilities than SRT.
- Scenarist Closed Caption (SCC). A closed captioning file format used in professional broadcast and digital media.
- Timed Text Markup Language (TTML). An XML-based W3C standard widely adopted in the television industry.
- QuickTime Text (QT.TXT). A text track within a QuickTime multimedia file, which stores subtitle or caption information synchronized with video and audio content.
- Cheetah Advanced Subtitling Protocol (CAP). A proprietary format used in professional broadcast environments, compatible with Cheetah’s closed captioning software solutions, renowned for its support of Asian languages and vertical text.
The importance of closed captioning
Whether you make product demos for Facebook or host in-depth webinars on your ecommerce site, any video marketing strategy can benefit from closed captioning. Here’s why:
- Increased accessibility. Captions allow hearing-impaired people as well as English as a second language (ESL) learners to better enjoy your content. A commitment to accessibility allows you to reach a wider audience.
- A more professional appearance. Subtitles can make your video look more polished. Since automatic captioning can be inaccurate, SRT ensures the captions read the way you want them to.
- Improved search engine optimization (SEO). Search engine algorithms tend to favor inclusive and engaging content. The text in SRT files can be crawled by search bots, which can boost visibility and search engine rankings.
- Ease of use. SRT files are easy to create and update, and are compatible with virtually all video platforms and players, including YouTube, VLC, and Windows Media Player.
- Flexible viewing environments. Captions allow your audience to watch videos on mute without disturbing others.
- Global expansion. Translated subtitles can help you reach a wider audience.
Elements of an SRT file
The SRT format is made up of blocks, each containing three parts: a counter, timecodes, and subtitle text. Blocks are separated by a blank line. You can add as many blocks as you need until the end of the video. Here’s more information about the elements of an SRT block:
- Counter. Each block starts on a new line with a number indicating its order in the video.
- Timecodes. The next line specifies the exact start and end times of when the caption should appear and disappear on screen. Timecodes are separated by a --> and use a precise format: hours:minutes:seconds,milliseconds. For example, 00:01:17,757 --> 00:01:23,770 designates a start time of 1 minute, 17 seconds, 757 milliseconds and an end time of 1 minute, 23 seconds, 770 milliseconds.
- Subtitle text. The next line contains the text of the caption, usually 40 characters or fewer.
- Blank Line. An empty line separates each caption block from the next, signifying its end.
How to create an SRT file in a text editor
An SRT file is a simple text file—you don’t need a fancy application to open or edit it: A no-frills text editor is enough to adjust the captions or fix timecodes, which is important for keeping the sequence accurate and avoiding confusion. You can use text editors like:
- Notepad
- Notepad++
- WordPad
- TextEdit (for Mac)
Here’s the “make it from scratch” approach:
1. Open a plain text editor such as Notepad (Windows) or TextEdit (Mac).
2. Label each subtitle block sequentially, starting with 1.
3. Enter the timecode for when the text should appear and disappear on the screen. The format must be hours:minutes:seconds,milliseconds --> hours:minutes:seconds,milliseconds.
4. Type in the subtitle content on a line below the timecode. Each caption block typically contains one or two lines. Limit text to about 40 characters per line for a better viewing experience. Split up longer subtitles.
5. Separate each block with a blank line to denote the end of one caption and the beginning of the next.
6. Repeat these steps until your video is fully captioned.
7. Save with an “.SRT” file extension.
Manual creation offers complete control, but it can be more time consuming for longer videos. For those, you might want specialized tools or services. Many services apply Automated Speech Recognition (ASR) to automatically generate the captions.
How to create an SRT file with specialized tools
Steps for specialized tools vary depending on the tool used, but here’s the general process:
1. Upload your video or add a link to an online video URL.
2. Select SubRip file (.SRT) from the available output file formats.
3. Download the SubRip text file. AI captioning might only take an hour, while human captioning might take one to two days.
4. Before downloading, review and edit the SRT file as needed. Even the best tools can misinterpret unclear audio or non-standard accents, so it's a good idea to double-check timing and accuracy. Many services include built-in editing tools for quick fixes.
There are plenty of free and paid tools for creating SRT files. Browser-based tools include Clipchamp, Kapwing, Riverside.fm, and HappyScribe. Desktop application options include free open-source options like Subtitle Edit and Aegisub, as well as paid software like Adobe Premiere Pro, DaVinci Resolve, Movavi Video Editor, and Final Cut Pro.
How to add an SRT file for viewing a video
When you add subtitles to your video, open the SRT file in a media player like VLC or Windows Media Player. Here’s how:
1. Download the SRT file from the video site.
2. Open the video file in your media player.
3. Go to the subtitle or captions menu. In VLC, click Subtitles > Add Subtitle File.
4. Select the .SRT file from your computer.
5. Captions will now appear during playback.
How to add an SRT file to a YouTube video
If you’ve uploaded a video to your YouTube channel, you can rely on YouTube’s automatic captions—or upload your own SRT file for more accurate, precisely timed subtitles. Here’s how to add an SRT subtitle file to your video on YouTube:
1. Sign in to YouTube Studio. Go to studio.youtube.com in your web browser and sign in using the Google account linked to your YouTube channel.
2. Select a video to edit and goto the Subtitles section. On the video details page, click the Subtitles tab.
3. Upload the SRT file. In the pop up window, click “Upload file.” Select the “With timing” subtitle type and continue, then browse to your SRT file and click “Open.”
4. Edit the video language. Make sure the language is correct. If not, click Edit to change it.
5. Review and publish. YouTube will process the file and display a preview. Review the captions, make any minor edits if necessary, and publish when you’re ready.
Your SRT captions are now available on your YouTube video. Viewers can turn them on or off using the CC (Closed Captions) button in the video player.
How to add an SRT file to a Facebook video
First you must name your SRT file correctly. Facebook has a precise, case sensitive naming convention for SubRip format (.srt) files. Note where the lowercase and uppercase characters go:
filename.[language code]_[COUNTRY CODE].srt.
For example, the language and country code for United States English is en_US. So the filename would look like this:
mypromovideo.en_US.srt.
Here’s how to add your SRT file to a Facebook video you’ve uploaded:
1. Click the notification or the date and time at the top of the post on your feed or timeline.
2. Click “Options” in the top right, then “Edit” post.
3. Click “Edit” from composer, then “Add captions.”
4. Click “Upload” next to “Upload captions,” then select the SRT file from your computer.
5. Click “Save.”
6. Repeat the steps for any other language you want to add.
SRT file FAQ
How do you apply an SRT file to a movie?
Download the SRT file, then open your video in a media player and load the file through the subtitle menu. For online videos, upload the SRT file to hosting platforms like YouTube or Facebook using their caption or subtitle upload tools. Follow the correct file naming conventions.
What program opens SRT files?
SRT files are plain text files used to make captions. They can be opened and edited with any basic text editor, like Notepad and TextEdit. To see the captions from an SRT file, use media player programs like YouTube, VLC, or Windows Media Player.
How do you convert an SRT file to a PDF?
Open the SRT file in a text editor or word processing program, then save or print it as a PDF. This preserves the text content and timestamps in a readable and shareable document format that looks consistent.
