VTT files for subtitles and closed captions

Subtitles and closed captions have become integral parts of the viewing experience, particularly for content that is consumed across different languages or by individuals with hearing impairments. One popular file format for subtitles and captions is VTT (WebVTT). In this guide, we’ll explore what VTT files are, how they are structured, how they can be created, and how they’re used for subtitles and closed captions.

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What is VTT file?

VTT stands for Web Video Text Tracks, and it's a file format used to display subtitles, captions, and other text-based information in HTML5 video players. The VTT format is designed to be easy to read and simple to work with, making it well-suited for web use. Most modern video platforms, such as YouTube, Vimeo, and HTML5 video players, support this format.

Although VTT files are most used for subtitles and captions, they can also include other types of text data like video descriptions, chapter titles, or metadata. One of the main benefits of VTT files is that they are easy to edit and can be easily integrated into websites and online video content.

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WEBVTT Example:

1WEBVTT  
2
300:00:01.000     -->     00:00:05.000 
4
5Hello! Welcome to our video. 
6
700:00:06.000    -->      00:00:09.000 
8
9Welcome to the second line of video. 

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How to open VTT files?

VTT files, which are often used for subtitles or captions, can be easily opened using a variety of tools. For basic viewing or editing, you can use a regular text editor. To do this, simply right-click on the VTT file and choose "Open with," then select a program like Notepad, Sublime Text, or Visual Studio Code (VS Code) if you have it installed. This approach allows you to view the file's text and make simple changes.

For a more specialized approach, consider using dedicated subtitle editing software. Programs like Aegisub or Subtitle Workshop provide enhanced functionality, such as time code adjustments, video preview, and other features that make editing subtitles more user-friendly and precise.

Whether you just need to open a VTT file or want to dive into editing it, both basic text editors and advanced subtitle tools can help you achieve your goal.

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Opening VTT files on android

1. Use a Compatible Media Player:

VTT files can be used as subtitle tracks in various media players like VLC or MX Player. Ensure you have one of these installed.

2.Playing with VLC:

• Open VLC and start playing the video you want to use with the VTT file.

• Tap on the screen to bring up the menu, then select Subtitles > Add Subtitle File.

• Navigate to your VTT file, select it, and the subtitles should appear during playback.

3. Using a Web Browser:

• If you prefer, you can also open VTT files in a web browser. Simply drag and drop the VTT file into the browser window, and it will display the text content.

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Opening VTT files on iOS

1. Using the files App:

• Open the Files app on your iPhone or iPad.

• Navigate to the location where your VTT file is stored (e.g., Downloads).

2. Viewing with a Text Editor:

• You can view the contents of a VTT file using any text editor available on iOS, such as TextEdit or similar apps. Just tap on the file to open it.

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How to edit VTT files

Editing a VTT file is a simple process:

1. Open the file: Use a text editor (like Notepad) or a subtitle editor (like Aegisub).

2. Make your changes: Modify the text or adjust time codes as needed.

3. Save your work: After making your changes, save the file to preserve your edits.

When editing VTT files, always double-check the time codes to ensure they match the intended timing in the video, so the subtitles remain in sync. With these easy steps, you can quickly update or customize your VTT subtitle files.

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What is SRT files and how it is different from VTT?

SRT (SubRip Subtitle) and VTT (WebVTT) are both popular file formats used for subtitles or captions in videos. They share the same general purpose but have some key differences in structure and use cases. Here's a detailed comparison:

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1. SRT (SubRip Subtitle)

File extension: .srt

Format: Plain text

Structure: SRT files are very simple. Each subtitle entry consists of:

• ‍Subtitle number: A sequential number indicating the order of the subtitles.

• Timecode: The start and end time when the subtitle appears on the screen, formatted as HH:MM:SS,MS --> HH:MM:SS,MS (hours, minutes, seconds, milliseconds).

• Subtitle text: The actual subtitle text, which can span multiple lines.

• Blank line: Separates each subtitle entry.

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Example:

11 
200:00:01,000 --> 00:00:04,000 
3Hello, world! 
4 
52 
600:00:05,000 --> 00:00:08,000 
7Welcome to the video!

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• Use cases: SRT is widely used in video editing, streaming platforms, and offline media players. It's compatible with almost every video player and editing software.

• Pros:
  • Very simple and easy to edit manually.
  • Widely supported across different platforms.

• Cons:
  • Limited to plain text. Does not support advanced styling (like colors, fonts, etc.).
  • No metadata support (e.g., descriptions or speaker identification).

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2. VTT (WebVTT)

File extension: .vtt

Format: Plain text (with a specific header)

Structure: VTT files are more flexible than SRT and allow additional features like styling and positioning. A VTT file begins with the header WEBVTT, and each subtitle entry is like an SRT file but can include extra metadata.

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Example:

1WEBVTT 
2 
31 
400:00:01.000 --> 00:00:04.000 
5Hello, world! 
6 
72 
800:00:05.000 --> 00:00:08.000 
9Welcome to the video!

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• Additional features:
  • VTT supports HTML-like formatting for subtitles (such as bold, italics, and other text styling).
  • You can add cue settings, which specify the alignment, position, and other properties of the subtitle on the screen.
  • VTT files allow you to add metadata (e.g., speaker identification or timestamps) and other advanced features for web video use.

• Use cases: WebVTT is specifically designed for use in web-based video players (e.g., HTML5 video tags). It's also used by platforms like YouTube and Vimeo.

• Pros:
  • More flexible with styling and positioning.
  • Supports richer features such as speaker identification, metadata, and additional formatting.

• Cons:
  • More complex than SRT, making it a bit harder to edit manually.
  • Less widely supported in non-web environments compared to SRT.

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Key differences:

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When to use each format

1. Use SRT When:

• You need a straightforward solution for basic captioning without any formatting requirements.

• You are working with platforms that primarily support SRT files.

2. Use VTT when:

• You require advanced styling options or need to include metadata in your captions.

• Your content is intended for web-based platforms that support HTML5 features.

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How do I check VTT file for errors?

To check for errors in VTT (Web Video Text Tracks) files, you can combine manual inspection with automated tools. Here’s a detailed guide to help you ensure your VTT files are free of errors.

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Manually

Use a text editor like Notepad, Sublime Text, or any subtitle editing software to open your VTT file.

1. Check for Common Errors:

• Time Codes: Ensure that all time codes are formatted correctly (e.g., 00:00:01.000 --> 00:00:05.000). Look for missing or extra zeros and ensure that the start time is always less than the end time.

• Cue Structure: Each cue should be separated by a blank line. Check for missing or extra blank lines between cues.

• Correct Formatting: Ensure that the header at the top of the file reads WEBVTT and that each cue follows the proper structure.

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2. Look for Syntax Issues:

• Verify that there are no typos in the cue text or formatting tags. For example, ensure that any HTML tags used for styling (like <b> or <i>) are properly closed.

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Automated tools for validation

Using online validators can save time and help catch errors you might miss manually. Here are some recommended tools:

1. W3C WebVTT validator:

This tool from the World Wide Web Consortium (W3C) checks if your VTT file adheres to the WebVTT specifications. You can upload your file or paste its content directly into the validator, which will highlight any syntax errors or structural issues found within the file.

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2. Subtitle tools WebVTT validator:

Another reliable option, this tool allows you to upload your VTT file or paste its content for validation. It provides detailed reports on any errors, such as incorrect time codes or formatting problems.

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3. Amara:

Amara is primarily known for collaborative subtitle creation but also offers features to validate VTT files. When you upload your VTT file, it inspects it automatically and suggests corrections for common mistakes.

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4. Debugging tools:

If you encounter specific issues while using VTT files in applications (like problems with captions not displaying), debugging tools can help identify issues related to formatting and syntax errors.

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Best practices

• Regular Validation: Make it a habit to validate your VTT files regularly, especially after making edits.

• Keep Backups: Always keep a backup of your original VTT files before making changes.

• Use Consistent Formatting: Maintain consistent formatting throughout your VTT files to avoid confusion and errors.

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How to convert a VTT file to a word file?

To convert a VTT file to a Word document, you can use various online tools that facilitate this process. Here’s a step-by-step guide on how to do it using some popular converters:

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Using OOONA

1. Access OOONA's Conversion Tool: Navigate to the OOONA website.

2. Select your File: Upload your VTT file using the provided interface.

3. Convert to Word Document: Choose the output format as Word Document (.docx) and initiate the conversion.

4. Download the Converted File: After conversion, download your Word document from the site.

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Using SubEasy.ai

1. Go to SubEasy.ai: Visit SubEasy.ai.

2. Upload the VTT File: Select your VTT subtitle file that you want to convert.

3. Start Conversion: Click on “Convert to Word” and wait for the process to complete.

4. Download Your Document: Once ready, download your converted Word file.

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How to Create VTT Files:

Creating VTT files can be done through various methods:

You can create a VTT file manually by using a simple text editor by following this structure:

1WEBVTT 
2
3
400:00:01.000 --> 00:00:05.000 
5
6This is the first subtitle line. 
7
800:00:06.000 --> 00:00:10.000 
9
10Here is the second line of subtitles. 

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Here's a step-by-step guide to help you create your own VTT files.

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Step 1: Understand the VTT File Format

A VTT file is a plain text file that includes timecodes and text for subtitles. The format consists of:

File header: A VTT file begins with the string WEBVTT at the top.

Subtitle entries: Each subtitle consists of:

1. Time range: Start and end time for the subtitle display in the format HH:MM:SS.MS --> HH:MM:SS.MS

2. Subtitle text: The text that appears in the video during that time frame.

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Step 2: Set Up a New File

1. Open a text editor (like Notepad on Windows or TextEdit on macOS).

2. At the very top of the file, add the header:

3. Save the file with a. vtt extension (for example, subtitles.vtt).

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Step 3: Add Subtitle Entries

Each subtitle entry should have the following structure:

• Timecode: The time range when the subtitle appears.

• Text: The subtitle text that should appear during the specified time range.

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Here’s an example:

1kotlin 
2
3WEBVTT 
4 
500:00:01.000 --> 00:00:05.000 
6Hello! Welcome to this video. 
7 
800:00:06.000 --> 00:00:10.000 
9In this tutorial, we will learn how to create VTT files. 
10 
1100:00:11.000 --> 00:00:15.000 
12Let’s get started!

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Timecode Format

The time format follows HH:MM:SS.MS, where:

• HH = Hours (optional, used if the video is longer than an hour)

• MM = Minutes

• SS = Seconds

• MS = Milliseconds (with three digits, e.g., 000)

The separator between the time range is -->.

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Step 4: Add Styling or Notes (Optional)

VTT files support optional styling and metadata. For example:

• Text formatting: You can use HTML tags like <b>, <i>, or <u> for bold, italics, and underline.

• Speaker labels: You can use speaker identifiers or notes.

Example with formatting:

100:00:01.000 --> 00:00:05.000 
2<b>Hello!</b> Welcome to this <i>video</i>.

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Step 5: Save and Test the File

1. Once you've added all the subtitles, save the file.

2. You can test the VTT file by adding it to a video player that supports captions (e.g., a browser, YouTube, or an HTML5 player).

For an HTML5 video player, you can link the VTT file in the HTML code like this:

1<video controls> 
2  <source src="your-video.mp4" type="video/mp4"> 
3  <track kind="subtitles" label="English" src="subtitles.vtt" srclang="en"> 
4</video>

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Step 6: Troubleshoot

• Ensure correct timecodes: Double-check that the times are in the correct format and that no two subtitles overlap in time.

• Correct encoding: Save your file as UTF-8 encoding to ensure compatibility.

• Check line breaks: Each subtitle should be on a new line with no extra spaces between them.

Example of a Full VTT File:

1vtt 
2
3WEBVTT 
4 
500:00:00.000 --> 00:00:02.000 
6Welcome to the tutorial! 
7 
800:00:02.500 --> 00:00:06.000 
9In this video, we’ll show you how to create VTT files for video captions. 
10 
1100:00:06.500 --> 00:00:10.000 
12Let’s get started. 
13 
1400:00:10.500 --> 00:00:14.000 
15First, you need a text editor. 
16 
1700:00:14.500 --> 00:00:18.000 
18Now, let’s move on to creating the actual file. 
19 
2000:00:18.500 --> 00:00:20.000 
21It’s easy! Just follow these steps. 

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Each caption block starts with a timestamp indicating when it should appear and disappear.

1. Using Online Tools: Many platforms offer tools to generate VTT files easily:

• Kapwing: Allows users to generate captions using AI technology and download them in VTT format.

• Rev: Provides a caption generator where you can upload videos or paste URLs to create VTT files

• Subtitle Edit Online: A free web-based tool that outputs standard VTT files without requiring video uploads.

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2. Conversion from Other Formats: If you have existing SRT files, you can convert them to VTT using various online converters. The process typically involves uploading your SRT file and selecting the output format as VTT.

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Best Practices for Implementing VTT Files

• Ensure Accuracy: Review the text for spelling and grammatical errors before finalizing your VTT file.

• Timing Matters: Make sure that the timing of each subtitle aligns well with the audio to enhance viewer comprehension.

• Accessibility Compliance: Adhere to accessibility standards by providing captions that cater to viewers with hearing impairments.

• Test Across Platforms: Before publishing your videos, test them on different platforms to ensure that the captions display correctly.

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Conclusion

Subtitles and closed captions have become essential tools for making videos accessible, engaging, and viewer-friendly. Whether you’re catering to a global audience or enhancing accessibility for individuals with hearing impairments, file formats like VTT and SRT provide a solid foundation. Each format has its unique advantages: SRT’s simplicity and universal compatibility, and VTT’s advanced styling and metadata features. By understanding their structures, uses, and differences, you can create, edit, and implement these files effectively to enhance the viewing experience.

At FastPix, we make handling subtitles and captions effortless. Whether you need to create, edit, or convert subtitle files, our platform offers powerful and user-friendly tools designed to save you time and ensure professional results. Check out our feature page to know more about what we provide.