Subtitle File Formats: SRT vs VTT + Free Converter (2027)

Q: What's the difference between SRT and VTT?

VTT starts with WEBVTT , uses a dot before milliseconds, and supports position and styling; SRT uses a comma and has no official styling. Web players need VTT.

Summary

SRT is the safest all-round format. VTT (WebVTT) is the web standard, with position and styling. ASS carries full styling. SBV is a simple platform format. TTML is the XML family used in broadcast and streaming. SCC carries broadcast caption data.

Choose by destination: what the player, platform or client spec accepts, not what looks most capable.

Keep one clean master (usually SRT) and convert to everything else, so edits happen once.

Create SRT and VTT from your video in Video to Subtitles, then convert free with our subtitle tools.

"Send the captions" sounds simple until someone asks which format. Subtitle file formats differ in how they write timestamps, whether they can position or style text, and which players and platforms accept them. Pick the wrong one and the file is rejected, the styling disappears, or captions play out of sync.

This guide compares the six subtitle formats you're most likely to meet, shows what each looks like, and tells you which to deliver for each destination, with a free converter for each common pair.

Need subtitles in the first place? Generate SRT and VTT from your video in one upload.

Subtitle formats at a glance

Format	Extension	Type	Styling and position	Typical use	Free VideoText tool
SubRip	`.srt`	Plain text	Not official	Editors, desktop players, most uploads	SRT to VTT, SRT to SBV, SRT to text
WebVTT	`.vtt`	Plain text	Cue settings and CSS	HTML5 video, web players, e-learning	VTT to SRT
Advanced SubStation Alpha	`.ass` / `.ssa`	Plain text with style sections	Full typesetting	Styled subtitles, fan and media workflows	ASS to SRT
SBV	`.sbv`	Plain text	None	One large video platform's caption editor	SBV to SRT
TTML (incl. DFXP, IMSC, EBU-TT profiles)	`.ttml` / `.xml` / `.dfxp`	XML	Regions and styles	Broadcast and streaming delivery	TTML to SRT
Scenarist Closed Caption	`.scc`	Hex-encoded caption data	Positioning, pop-on and roll-up	North American broadcast	No converter; see SCC

All the converters above run in your browser, and your file isn't uploaded.

SRT vs VTT: the comparison most people need

	SRT	VTT
Header	None	`WEBVTT` on the first line
Timestamp	`00:01:23,456` (comma)	`00:01:23.456` (dot), hours optional
Cue numbers	Expected	Optional identifiers
Position and styling	Not official	Cue settings (`line`, `position`, `align`…) and CSS
Speaker tags and comments	No	`<v Name>` voice spans and `NOTE` blocks
HTML5 `<track>`	Not supported	Supported
Accepted by	Almost every editor, player and platform	Web players and most platforms

Use SRT for editing software, desktop players and uploads where you aren't sure what's supported. Use VTT for anything that plays in a browser, or when you need captions moved away from on-screen text.

Converting is lossless for text and timing in both directions. VTT to SRT drops VTT-only features (cue settings, voice tags, classes), because SRT can't store them. Never just rename the extension: the header and timestamp separator must change too.

Deep dives: what is an SRT file? and what is a VTT file?

Convert now: SRT to VTT · VTT to SRT

The other formats, in brief

ASS and SSA

ASS (Advanced SubStation Alpha) and its older form SSA store style definitions in sections at the top of the file and dialogue lines underneath, with override tags for position, colour, font and motion. Excellent for typeset, styled subtitles; poorly supported by mainstream editors and platforms. The free ASS to SRT converter keeps every line of dialogue and its timing and strips the styling.

Need styled captions that look the same everywhere? Burn them into the picture. Subtitle Style Studio can also export a styled ASS file, which needs the approved fonts installed to display as designed. See best font for subtitles.

SBV

A minimal plain-text format: start and end times on one line separated by a comma, with dots before the milliseconds, then the text. No cue numbers and no styling. Convert with SBV to SRT or the reverse with SRT to SBV.

TTML, DFXP, IMSC and EBU-TT

TTML (Timed Text Markup Language) is a W3C XML standard. Distributors usually require a constrained profile, such as IMSC or EBU-TT, rather than "any TTML", and DFXP is an earlier name for the same family. When a spec says "TTML", ask which profile, frame rate and styling are allowed. The free TTML to SRT converter turns these files into SRT for editing or review. Glossary: TTML.

SCC

SCC (Scenarist Closed Caption) stores CEA-608 caption data as hexadecimal codes paired with SMPTE timecodes. It's tied to a frame rate and drop-frame convention, and it's used in broadcast and finishing rather than on the web. Conversion either way loses or has to invent detail. VideoText doesn't convert SCC; follow your broadcaster's tooling. Glossary: SCC.

Which subtitle format should you deliver?

Destination	Deliver	Notes
Your own website (HTML5 video)	VTT	Required by the `<track>` element
Most video and course platforms	SRT or VTT	Check the upload page; SRT is the safe default
A video editor or edit suite	SRT	Widest import support
Social feeds that autoplay muted or ignore subtitle files	Burned-in MP4	Use Burn Subtitles
Broadcast or streaming distributor	Whatever the spec names (often a TTML profile or SCC)	Follow the spec exactly
Translation vendor or reviewer	SRT	Easiest to diff and review
A transcript for reading	TXT or DOCX	Strip timings with SRT to text; see transcript examples

Forced subtitles (captions only for foreign-language dialogue or on-screen text) are usually delivered as a separate file in the same format as the main track. See what forced subtitles are.

The one-master workflow

Keep one clean master and generate everything from it:

Create the master from the video in Video to Subtitles or Video to SRT. One upload gives you SRT and VTT from the same cues. Free accounts handle files up to 30 minutes, with no card; Pro handles files up to 4 hours.
Check it in the free subtitle validator, which reads SRT and VTT line by line in your browser.
Repair overlaps, long lines and fast cues in Fix Subtitles.
Translate in Translate Subtitles: SRT stays SRT, VTT stays VTT, across 104 target languages, with every cue's timing kept.
Convert or burn in for each destination.

Edit the master, never the converted copies. Fix a typo once and regenerate.

Free subtitle downloads include two short watermark cues (one at the start, one after the last cue). Pro removes them and lets you edit cues.

Start your master file: Video to Subtitles, free with an account.

Common format mistakes

Renaming instead of converting. An SRT renamed .vtt looks right and fails to load.
Wrong encoding. Save subtitle files as UTF-8, or accented and non-Latin characters break.
Relying on styling that won't survive. SRT styling tags are honoured inconsistently; VTT cue settings depend on the player.
Ignoring the frame rate for SCC and TTML deliveries, which causes drift.
Editing converted copies. Your SRT and VTT drift apart and nobody knows which is right.

If a client has already bounced your file, see subtitle file rejected by a client.

FAQ

What is the most common subtitle file format? SRT. It's plain text with no header or styling, so almost every editor, player and platform reads it.

What's the difference between SRT and VTT? VTT starts with WEBVTT, uses a dot before milliseconds, and supports position and styling; SRT uses a comma and has no official styling. Web players need VTT.

Which subtitle format is best? The one your destination accepts. SRT is the safest default, VTT for the web, a TTML profile or SCC when a broadcast spec requires it.

Can I convert between subtitle formats for free? Yes. Our free converters handle SRT to VTT, VTT to SRT, ASS to SRT, SBV to SRT, SRT to SBV and TTML to SRT in your browser.

Can I get SRT and VTT from one video? Yes. Video to Subtitles produces both from the same cues.

Next step

Create SRT and VTT from your video, check them in the validator, and convert free in our subtitle tools. For long videos, cue editing and clean downloads, Pro is $14.99/month or $120/year, with files up to 4 hours and subtitle translation into 104 languages. See our refund policy.

Related guides and tools

Sources: W3C, "WebVTT: The Web Video Text Tracks Format" (https://www.w3.org/TR/webvtt1/); W3C, "Timed Text Markup Language 2 (TTML2)" (https://www.w3.org/TR/ttml2/) and "TTML Profiles for Internet Media Subtitles and Captions (IMSC)" (https://www.w3.org/TR/ttml-imsc1.2/); CTA-608-E (line 21 caption data) for SCC; VideoText SRT to VTT, VTT to SRT, ASS to SRT, SBV to SRT, SRT to SBV, TTML to SRT, SRT to text, subtitle validator, Video to Subtitles, Fix Subtitles, Translate Subtitles, Subtitle Style Studio, Burn Subtitles and pricing pages and the SCC and TTML glossary entries, https://videotext.io/subtitle-tools, https://videotext.io/video-to-subtitles, https://videotext.io/translate-subtitles, https://videotext.io/glossary/scc and https://videotext.io/glossary/ttml (checked October 31, 2026).