What Is a Subtitle?

If you searched "what is a subtitle," you probably meant one of three things:

1. Video subtitle (translation of dialogue)

The most common meaning in 2026. On-screen text translating spoken audio from one language to another. Used for foreign films, international TV shows, YouTube videos with multilingual audiences, and language learning. Stored in subtitle file formats (SRT, VTT, TTML, ASS).

2. Book or article subtitle (secondary title)

The clarifying or descriptive phrase that follows a main title, usually separated by a colon. Examples:

• Sapiens: A Brief History of Humankind — "A Brief History of Humankind" is the subtitle.
• Atomic Habits: An Easy & Proven Way to Build Good Habits — the subtitle explains the book's promise.
• Lord of the Rings: The Fellowship of the Ring — the subtitle distinguishes the volume.

Subtitles in this sense help readers understand what the book is about beyond a clever main title, support discoverability in search and bookstore browsing, and structure series within a parent title.

3. Writing subtitle (subheading)

In structured writing — articles, technical documentation, academic papers — a subtitle is a heading nested under a primary heading. In HTML, this corresponds to <h2> under an <h1>, or <h3> under an <h2>. The dictionary uses this meaning when defining subtitle as "a secondary or subordinate title."

The rest of this page focuses on the video meaning, which is what most people are looking for.

Several specific subtitle types exist, distinguished by what they include and who they're for:

Translation subtitles (the standard kind)

Same-content text translated from the source language to the viewer's language. Designed for hearing viewers. Doesn't include sound effects or speaker IDs. Most subtitles you see on Netflix, YouTube, or in foreign cinema are this type.

Same-language subtitles (transcription subtitles)

Display the dialogue in the same language as the audio. Used when audio is unclear (heavy accents, low-quality recording), when viewers are language learners, or when context demands it (loud public spaces, sound-off viewing on social media). Increasingly popular among Gen Z viewers — surveys show 70-80% of Gen Z keeps subtitles on even for native-language content.

SDH (Subtitles for the Deaf and Hard of Hearing)

A hybrid format. SDH includes both translation (or same-language dialogue) AND non-speech audio descriptions and speaker IDs that closed captions provide. Streaming platforms increasingly offer SDH tracks alongside standard subtitles for each target language. The Netflix subtitle picker labels these as "English [SDH]" or similar.

Forced subtitles

Subtitles that appear automatically only for specific moments — usually when a foreign-language line is spoken in an otherwise-native-language film, or when on-screen text needs translation. Star Wars famously uses forced subtitles for Greedo's Huttese dialogue. Different from regular subtitles, which the viewer turns on for the entire film.

Open subtitles

Burned permanently into the video frame. The viewer cannot turn them off. Used in social media (TikTok, Instagram, YouTube Shorts) where many viewers watch with sound off, in cinema for accessibility screenings, and in hardcoded translations for distribution where the player may not support text tracks.

Closed subtitles

Delivered as a separate text track. The viewer toggles them on or off. The standard for streaming platforms, broadcast TV, and HTML5 web video. Stored in SRT, VTT, or TTML files.

The terms are used interchangeably by the public, but they have specific technical meanings:

The shorthand: subtitles are for language; captions are for accessibility. See the full closed captions vs subtitles comparison for legal compliance details, file format implications, and side-by-side examples.

A subtitle file is plain text — readable in any text editor — that pairs lines of translated text with start and end timestamps. The video player reads the file and overlays the text at the right moment.

The most common subtitle file formats

• SRT (.srt) — SubRip Subtitle. The most universally supported subtitle format. Simple plain text with timecodes. Used by YouTube, Vimeo, video editors, and almost every player. Full SRT format reference →
• VTT (.vtt) — Web Video Text Tracks. The W3C standard for HTML5 video. Required for the HTML <track> element. Full VTT format reference →
• TTML / DFXP (.xml). XML-based format used by Netflix, Disney+, and other streaming platforms with rich styling needs.
• iTT (.itt). Apple's iTunes Timed Text format for Apple TV / iTunes content submission.
• ASS / SSA (.ass, .ssa). Advanced SubStation Alpha — used in fansubs and styled subtitling that requires fonts, colors, and positioning beyond what SRT supports.
• SUB / IDX (.sub + .idx). Image-based subtitle format used in DVD rips. Each subtitle is stored as an image rather than text — older format, less editable.

Example SRT subtitle (English subtitles for a Spanish video)

1
00:00:00,000 --> 00:00:03,200
What's your name?

2
00:00:03,300 --> 00:00:05,500
My name is Maria.

3
00:00:05,800 --> 00:00:08,400
Nice to meet you, Maria.

The timestamps tell the player when to display each line and when to remove it. The Spanish original audio plays normally — the subtitle file just tells the player what English text to show on top.

Three workflows in 2026, ranging from fully automated to fully manual:

1. AI translation (fastest)

Automated subtitling has gotten genuinely good. The workflow:

1. Generate a transcript in the source language using TranscribeVideo.ai, Whisper, or similar AI transcription tool. For YouTube, the video already has auto-captions you can extract.
2. Run the transcript through DeepL, Google Translate, or ChatGPT for translation into the target language.
3. Format the translated text as an SRT or VTT file with the same timestamps as the source.
4. Upload to your video platform.

Quality on common language pairs (English ↔ Spanish, English ↔ French, English ↔ German) is now publishable for casual content. For high-stakes material (cinema, marketing, brand video), human review is still recommended.

2. AI draft + human review (recommended for serious content)

Take the AI-translated subtitles and have a native speaker review and refine. Common fixes: idioms that translate literally instead of adapting, cultural references that need localisation, line-break placement for reading flow, and timing adjustments where translated lines don't match audio length. Cost: typically $1-3 per minute of video for a freelance subtitle reviewer.

3. Professional subtitling (broadcast and cinema)

Services like Iyuno-SDI, Deluxe, and Visual Data offer broadcast-grade subtitling. Costs run $5-20 per minute depending on language pair and turnaround. Required for major-platform submissions (Netflix, Disney+) which have strict subtitle quality specifications.

YouTube

1. Open YouTube Studio → Subtitles
2. Click your video → Add language → choose target language
3. Click Add → choose Upload file (and pick With timing)
4. Upload your .srt or .vtt file
5. Save

Viewers can then select your language from the CC button while playing.

Vimeo

1. Open the video → Settings → Distribution → Subtitles
2. Click Add → Upload subtitle file
3. Choose Subtitles (not Captions) → select language
4. Upload .srt or .vtt

HTML5 video on your own website

<video controls>
  <source src="video.mp4" type="video/mp4">
  <track src="english.vtt"
         kind="subtitles"
         srclang="en"
         label="English">
  <track src="spanish.vtt"
         kind="subtitles"
         srclang="es"
         label="Spanish">
</video>

Note kind="subtitles" not "captions" — the kind attribute is how the browser knows the difference.

Premiere Pro / Final Cut Pro / DaVinci Resolve

All three accept SRT files via File → Import (or drag onto the timeline). The subtitle becomes a separate track that can be styled, repositioned, or burned in for export.

Subtitle usage among hearing viewers has surged in the past five years. Multiple surveys (Preply 2023, YouGov 2024, Stagetext UK 2024) consistently find:

• 70-80% of Gen Z (born 1997-2012) watches video content with subtitles enabled, even when there's no language barrier and no hearing impairment.
• Among adults under 30 globally, the figure is around 55%.
• Even among hearing adults over 50, subtitle usage exceeds 30%.

Reasons cited:

• Comprehension. Modern TV mixes prioritise atmospheric sound over dialogue clarity. Subtitles catch what the audio mix loses.
• Sound-off viewing. Phone in coffee shop, train, airport, open office — subtitles are the only way to follow the content.
• Multitasking. Watching while doing something else; subtitles allow looking away while still following.
• Accent unfamiliarity. Subtitles help with regional accents within the same language.
• Vocabulary and proper nouns. Subtitles spell out unfamiliar words, easier than parsing them by ear.
• Faster reading speed than listening. Many viewers read faster than dialogue is delivered, allowing them to absorb content quicker.

The implication for content creators: subtitles aren't optional for accessibility anymore — they're a core part of how video is consumed across all demographics. A video without subtitles loses meaningful watch time and engagement compared to one with subtitles, regardless of audience demographics.