Format guide
What is SRT?
SRT file format is a simple SubRip subtitle file with timecodes and plain text cues, created by SubRip community (2000s). SRT is the most common subtitle exchange format: numbered cues with start/end times. Players and editors everywhere understand it. Convert to VTT for native HTML5 video tracks on the web.
SRT format specifications
- Full name
- SRT file format
- Kind
- structured data
- File extension
- .srt
- MIME type
- application/octet-stream
- Developer / standard
- SubRip community · 2000s
- Compression
- none or container
- Quality model
- Lossless / not lossy
- Container
- No / single bitstream typical
- Common codecs
- —
- Technical sources
- —
- Transparency
- Not supported
- Animation
- No (still / non-animated typical use)
- Typical size
- Tiny
- Browser support
- Use WebVTT in HTML5; convert SRT→VTT for <track>
- Compatibility
- Understood by VLC, most desktop editors, and caption pipelines; convert to VTT for native HTML5 <track> elements
SRT compression & quality
SRT compression: none or container. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Tiny. Quality note: Plain text; no advanced styling in classic SRT
Quality: Plain text; no advanced styling in classic SRT
Typical size: Tiny
Transparency & animation
SRT does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
SRT is a still-media or non-animated format in typical use. Use GIF, APNG, video, or animated WebP when you need motion.
SRT metadata
Usually none beyond encoding/BOM — structure is the content. Comments allowed in YAML/TOML.
Best use cases for SRT
- Movie and course subtitles
- Exchange between editors
- Burn-in workflows after conversion
- Multi-language caption packs
When to avoid SRT
- Fancy styled captions (use VTT/ASS)
- Frame-accurate pro deliverables without checking fps
- Binary caption formats required by broadcasters
- Assuming every streaming platform accepts raw SRT
Advantages
- Simple
- Universal
- Easy to edit in text editors
- Diff-friendly
Disadvantages
- Minimal styling
- FPS/timing pitfalls
- Encoding issues with non-Latin text
- Not the web-native track format
Compatibility
Understood by VLC, most desktop editors, and caption pipelines; convert to VTT for native HTML5 <track> elements
Browsers: Use WebVTT in HTML5; convert SRT→VTT for <track>
Software support
- VLC
- Subtitle Edit
- Premiere
- HandBrake workflows
- Format Convertly
Device support
- Desktops and media players; phones via player apps
- Modern desktops
- Phones and tablets with compatible apps
How to open SRT
Open in a text editor or Subtitle Edit; load alongside video in VLC to verify timing.
How to convert SRT
Convert SRT to VTT for HTML5 players in Format Convertly’s browser tools so caption files never need to leave your machine.
Popular SRT conversions
Convert to SRT
Related formats
SRT tools
Tools extend the format graph beyond one-off conversion — compression, metadata, and utilities for real workflows.
SRT FAQ
What is a SRT file?
SRT is a simple SubRip subtitle file with timecodes and plain text cues. SRT is the most common subtitle exchange format: numbered cues with start/end times. Players and editors everywhere understand it. Convert to VTT for native HTML5 video tracks on the web.
Is SRT lossy or lossless?
SRT is typically lossless or non-destructive in common use (none or container).
Does SRT support transparency?
SRT does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
How do I open a SRT file?
Open in a text editor or Subtitle Edit; load alongside video in VLC to verify timing.
How do I convert SRT privately?
Convert SRT to VTT for HTML5 players in Format Convertly’s browser tools so caption files never need to leave your machine. Format Convertly keeps processing in your browser so files are not uploaded to a conversion server.
Are my SRT files uploaded on Format Convertly?
No. SRT conversion runs in your browser. Files are not sent to Format Convertly servers for processing.