How to Add Subtitles and Captions to Video

A lot of online video is watched without sound. Viewers may be scrolling through social media, commuting, sitting in an open-plan office or simply choosing not to turn the audio on.

If your video relies entirely on speech, those viewers may miss the message.

Captions and subtitles make videos easier to understand without sound. They also improve accessibility and allow the same video to work across websites, social platforms, internal communications and live presentations.

This guide explains the difference between captions and subtitles, the main ways to add them and how to choose the right format for each platform.

What is the difference between subtitles and captions?

The terms are often used interchangeably, but they have different meanings.

Subtitles generally display spoken dialogue. They are commonly used when translating dialogue from one language into another.

Captions provide a more complete text version of the audio. As well as dialogue, they may identify speakers and describe meaningful sounds such as music, applause or a phone ringing.

For example:

[upbeat music]
RYAN: Welcome to Dream Engine.

Captions are generally the better option when accessibility is the priority because they provide information that would otherwise only be available through the soundtrack.

For everyday online video, many people still use the word “subtitles” to describe both formats. What matters most is that the text is accurate, readable and appropriate for the audience.

Why captions matter

Captions make video useful in more situations.

They allow people to follow the message when:

• their device is muted
• they are in a noisy or shared environment
• the speaker’s accent is unfamiliar
• English is not their first language
• the recording contains technical terms
• they are deaf or hard of hearing

Captions can be particularly important for government departments, universities, healthcare organisations and other organisations with public-facing or regulated content.

They can also improve comprehension and message retention. However, captions need to be accurate and well timed. Poor automatic captions can misrepresent names, technical terminology and important instructions.

The three main ways to add captions

There are three practical approaches:

1. Upload a separate caption file
2. Use captions generated by the publishing platform
3. Embed the captions permanently into the video

The right option depends on where the video will appear and how much control you need.

1. Separate caption files

A separate caption file, sometimes called a sidecar file, is uploaded alongside the video.

SRT is one of the most widely supported caption-file formats. It contains the dialogue and the timecodes that control when each caption appears.

Platforms such as YouTube, Facebook, LinkedIn and Vimeo can use caption files, although their upload processes and requirements vary.

Separate caption files have several advantages:

• viewers can turn captions on or off
• the text can adapt to different screen sizes
• captions can be corrected without re-exporting the video
• multiple languages can be supplied
• the video remains free of permanently embedded text

For websites and video platforms that support closed captions, this is usually the preferred accessibility option.

2. Platform-generated captions

Many social and video platforms can automatically generate captions from the soundtrack.

This can be convenient, but automatically generated text should always be reviewed before publication. Names, industry terminology and Australian place names are common sources of mistakes.

Some platforms also provide caption-design tools. Instagram, for example, offers automatic captions and a Captions sticker for eligible Reels and Stories.

These captions are added through Instagram rather than uploaded as a separate SRT file. Availability and controls can vary by account, region and content type.

Platform-generated captions are useful when:

• the video is being published on one platform
• a fast social-media workflow is required
• the captions can be checked and corrected before publishing

If the same video will be used across several platforms, preparing your own approved transcript or caption file gives you a more reliable source version.

3. Burnt-in captions

Burnt-in captions are permanently embedded into the video image during editing. They are also known as open captions.

Because they form part of the picture, viewers cannot turn them off.

Burnt-in captions are useful when:

• captions need to remain visible at all times
• a platform does not accept separate caption files
• the video will be played at an event or conference
• playback conditions cannot be controlled
• captions need to follow a specific brand style
• a social-media cut-down needs prominent on-screen text

Burnt-in captions provide greater control over font, colour, size and position. The limitation is that the text cannot adapt to the viewer’s device or preferences.

They can also create problems if text is placed beneath interface elements used by Instagram, TikTok or other mobile platforms. Important text should remain inside the platform’s safe area.

Which caption method should you use?

Where the video will appear	Recommended approach
YouTube or Vimeo	Upload an accurate caption file and keep the clean video master
Business website	Use an accessible video player with closed captions and consider providing a transcript
Facebook	Upload an SRT file or carefully review Facebook’s generated captions
LinkedIn	Use an uploaded caption file where available, with a burnt-in version for important social cut-downs
Instagram Reels or Stories	Use Instagram’s caption tools or upload a version with carefully positioned burnt-in captions
Conference or event screen	Use burnt-in captions when the text must always be visible
Multilingual video	Supply separate caption files for each language where the platform supports them
Internal training	Use closed captions where possible and provide a transcript when employees may need a searchable reference

A useful delivery package often includes:

• one clean master video
• one accurate English SRT file
• one version with burnt-in captions for social media
• additional caption files for other languages when required

This provides flexibility without having to recreate the edit later.

How to create an SRT caption file

An SRT file is a plain-text document. Each caption contains:

1. A sequence number
2. A start and finish timecode
3. The caption text
4. A blank line before the next caption

A correctly formatted example looks like this:

1
00:00:01,000 --> 00:00:05,000
Welcome to this guide to video captions.

2
00:00:05,500 --> 00:00:09,000
We will look at the main delivery options.

Notice that SRT timecodes use a comma before the milliseconds.

Save the file as plain UTF-8 text with the .srt extension. On a Mac, TextEdit needs to be switched to plain-text mode before saving.

Although an SRT file can be created manually, captioning software and professional editing programs can generate the initial timing automatically. The text and timing should still be reviewed by a person before delivery.

How to make captions readable

Accurate words are only part of good captioning. Viewers also need enough time to read them.

As a practical guide:

• use no more than two lines at a time
• break lines at natural points in the sentence
• keep captions synchronised with the speaker
• remove captions when the speech finishes
• identify speakers when it is not visually obvious
• include important sounds where accessibility is required
• use strong contrast between the text and background
• avoid covering faces, graphics or important actions
• check the captions on a mobile screen before publishing

The Australian Government Style Manual recommends keeping caption blocks short, with no more than 42 characters per line, and reviewing both accuracy and timing before publication.

Uploading an SRT file to YouTube

YouTube supports SRT and several other caption formats.

To upload an SRT file:

1. Open YouTube Studio.
2. Select the video.
3. Open the Subtitles section.
4. Choose the required language.
5. Upload the caption file.
6. Review the timing and text.
7. Publish the captions.

YouTube requires basic SRT files to be saved as plain UTF-8 text.

Adding captions to Facebook

Facebook allows Page owners to upload SRT files, generate captions automatically or create captions manually.

The exact interface may change, but caption controls are generally available through the video’s editing or video-options menu.

Facebook also has a specific naming convention for uploaded SRT files. Check the current Meta instructions before delivery, particularly when supplying more than one language.

Adding captions to Instagram

For most organic Instagram workflows, you cannot upload a separate SRT file in the same way as you can on YouTube or Vimeo.

Instead, you can:

• use Instagram’s automatic caption controls
• add the Captions sticker to eligible Stories or Reels
• upload a version with captions embedded during editing

Always review automatically generated captions. If a video contains names, technical information or important instructions, professionally prepared burnt-in captions may provide greater accuracy and visual consistency.

Do captions improve video SEO?

Captions may help video platforms understand the spoken content of a video, particularly when the platform processes the caption file directly.

However, captions are not a shortcut to higher Google rankings.

Google’s video-search guidance places greater emphasis on factors such as:

• a crawlable page containing the video
• a clear page title and description
• an accessible video player or file
• a stable, high-quality thumbnail
• accurate video metadata
• VideoObject structured data where appropriate
• a video sitemap for larger libraries

The strongest reasons to include captions are accessibility, comprehension and flexibility. Any discoverability benefit should be treated as an additional advantage rather than a guaranteed SEO result.

Should you use automatic captioning?

Automatic transcription is a useful starting point, but it should not be treated as the finished product.

Common errors include:

• people’s names
• business and product names
• acronyms
• technical terminology
• Australian place names
• words spoken over music or background noise

For casual social content, correcting the major errors may be enough. For training, healthcare, government, legal or safety-related material, the full caption file should be checked carefully against the recording.

Need help adding captions to your videos?

The best captioning approach depends on the video, audience and delivery platforms.

Dream Engine can provide:

• accurate caption and subtitle files
• burnt-in captions for social media
• multilingual caption versions
• transcripts
• vertical, square and widescreen video versions
• caption corrections for existing videos
• accessible delivery packages for websites, training and internal communications

Our video editing team can prepare the right combination of clean masters, caption files and platform-ready versions for your project.

Get in touch to discuss what you need.