Subtitle Format Converter

Convert between SRT, VTT (WebVTT), ASS/SSA, and LRC subtitle formats online. Auto-detect input format with preview.

1.0.0
Version
Auth
Batch

About Subtitle Format Converter

Subtitle formats are a four-way standoff. SRT is the universal lowest-common-denominator (every video player reads it, but it has no styling). VTT (WebVTT) is what HTML5 video and most modern streaming platforms want. ASS/SSA is the format anime fans and karaoke workflows use because it supports rich styling, positioning and fades. LRC is the lyrics-with-timestamps format every music player consumes. The wrong format and your subtitles show up as raw text, with broken timing, or not at all.

This subtitle converter handles all four formats in any combination. The detector reads the file's first lines and identifies the format (and the text encoding — UTF-8, GBK, Big5, Shift-JIS) with a confidence score. The conversion preserves the timing precisely — millisecond timestamps survive the round-trip even when going from a richer format (ASS with styles) to a poorer one (SRT plain text). Format-specific features that the target doesn't support are dropped gracefully rather than garbled. The before/after preview lets you spot a misread encoding or wrong target format before paying for the full conversion. Files up to 10 MB, which covers a full-feature-film subtitle plus any reasonable amount of styling metadata.

Use it to convert a downloaded SRT into VTT for an HTML5 video tag, pull ASS karaoke subtitles into plain SRT before sending to a client who doesn't have an ASS-aware player, share an LRC lyrics file as SRT for a video editor, normalise a mixed-format subtitle archive into one consistent format, or just open one .ass file someone sent without firing up Aegisub.

Subtitle Format Converter Use Cases

  • Embedding SRT-only subtitles into an HTML5 video tag (needs VTT)
  • Sending an ASS-styled anime subtitle to a client whose player only reads SRT
  • Importing an LRC lyrics file into a video editor that expects SRT
  • Normalising a mixed-format subtitle archive into one consistent format
  • Translators converting between styling-rich and plain-text formats during translation
  • Quick open of a .ass or .ssa someone forwarded without firing up Aegisub
  • Streaming workflows needing WebVTT but receiving SRT from a captioning vendor

Subtitle Format Converter Features

  • Converts between SRT (universal plain-text), VTT (WebVTT for HTML5), ASS/SSA (anime/karaoke styled), and LRC (lyrics)
  • Auto-detects input format from the file's first lines and reports a confidence score
  • Encoding detection across UTF-8, GBK, Big5, Shift-JIS so Chinese and Japanese subtitles don't garble
  • Timing preserved precisely through the round-trip — millisecond timestamps survive even cross-format conversion
  • Format-specific features (ASS styles, positioning, fades) are dropped gracefully when the target doesn't support them
  • Before/after preview shows what's being converted so you can spot a misread encoding before downloading
  • Files up to 10 MB processed in a stateless serverless function and discarded immediately after the response

How to Use Subtitle Format Converter

Upload your subtitle file

Drag-and-drop a .srt, .vtt, .ass, .ssa or .lrc file (up to 10 MB). The detector identifies the format and encoding from the file's first lines — no need to specify.

Click Detect (optional)

The detect action shows the inferred format, encoding with a confidence score, entry count and total duration. Useful for confirming you're starting from what you think you are — especially with Chinese or Japanese files where encoding misreads are common.

Pick the target format

SRT for maximum compatibility. VTT for HTML5 video and web streaming. ASS or SSA for styled anime or karaoke playback. LRC for music players that want synced lyrics. The conversion is one-pass.

Click Convert

The serverless converter walks the file, preserves the timing, and emits the target format. Styling that the target doesn't support (ASS colour, position, font) is dropped to plain text rather than garbled into the output.

Preview and download

The before/after preview shows the source vs converted text side by side. Confirm timing looks right and characters render correctly before downloading. The result is UTF-8 encoded regardless of the input encoding.

Subtitle Format Converter FAQ

No. The file is uploaded to a stateless serverless function, parsed and converted, and discarded immediately after the response. Nothing is logged to durable storage. Subtitle files for unreleased media are sometimes embargoed; for those, the Python pysubs2 library does this offline in a few lines.

SRT (SubRip — universal plain text with millisecond timestamps), VTT (WebVTT — the HTML5 standard, similar to SRT but with cue settings), ASS / SSA (Advanced SubStation Alpha — styled subtitles used by anime fan-sub groups and karaoke), LRC (synced lyrics with centisecond timestamps). The four formats cover roughly 95% of subtitle files in the wild.

Plain text is preserved; styling is dropped. SRT has no way to express ASS's positioning, colours, fonts, fades, karaoke timing or 3D rotation, so those are removed cleanly rather than left as raw \pos{} tags in the output text. If you need rich styling preserved, stay in ASS or convert to VTT (which supports a richer subset than SRT).

The detector tries UTF-8 strict first. If that fails, it falls back to GBK (the standard for Chinese files), Big5 (Taiwanese), Shift-JIS (Japanese) and Latin-1 as a permissive last resort. A confidence score is reported so you can tell when the detector is guessing. All output is written in UTF-8 regardless of the input encoding.

Yes. Timestamps are read as a precise number of milliseconds (or centiseconds for LRC), held internally with full precision, and re-emitted in the target format's native time syntax. SRT's HH:MM:SS,mmm and VTT's HH:MM:SS.mmm and ASS's H:MM:SS.cc all round-trip without drift. LRC's centisecond resolution is the loose end — converting to LRC and back loses sub-10ms precision.

10 MB. This covers a full-feature-film subtitle plus any reasonable amount of styling metadata — a typical two-hour film SRT is around 50 KB, an ASS with karaoke styling can run several MB but rarely more. For anything larger (a multi-language stacked .ass with embedded fonts), use the offline Aegisub or pysubs2 tools.

Subtitle Edit and Aegisub are full subtitle editors — the right tools when you're authoring or heavily editing. This converter is the narrowest version of the task: format A in, format B out, encoding handled, done. Useful when the job is a one-off conversion and you don't want to install a full editor for it.

Supports SRT, ASS, SSA, VTT, LRC formats, max 10MB
Select the subtitle format you want to convert to

Upload a subtitle file to detect its format and convert

Supported: .srt, .vtt, .ass, .ssa, .lrc

Subtitle Format Converter Tutorial

Why Convert Subtitle Formats?

Different media players and streaming platforms require different subtitle formats. Using the wrong format means your subtitles simply will not load. Here is when you need each format:

SRT (SubRip Text)

The most widely supported subtitle format. Works with VLC, MPC-HC, PotPlayer, Plex, and most desktop players. Simple text-based format with sequential numbering and timestamps. Best choice when you need maximum compatibility.

VTT (WebVTT)

The web standard for HTML5 video subtitles. Required by browsers for the <track> element. Used by YouTube, Netflix, and modern streaming platforms. If you are building a website with video, you need VTT.

ASS/SSA (Advanced SubStation Alpha)

Advanced format with rich styling support: custom fonts, colors, positioning, and animations. Popular in anime fansubs and karaoke. Use ASS when you need styled subtitles with visual effects.

LRC (Lyrics)

Synchronized lyrics format used by music players. Each line has a timestamp for karaoke-style display. Common in music apps like foobar2000, AIMP, and mobile music players.

How to Convert
  1. Upload your subtitle file (.srt, .vtt, .ass, .ssa, or .lrc)
  2. The tool auto-detects the source format and shows file info
  3. Select your target format from the dropdown
  4. Click "Convert Format" to process
  5. Preview the result and download the converted file
Common Conversion Scenarios
  • SRT to VTT: Embedding subtitles in HTML5 web video players
  • VTT to SRT: Using web subtitles in desktop media players
  • ASS to SRT: Stripping styling for simpler players that do not support ASS
  • SRT to ASS: Adding styling capabilities to plain subtitles
  • SRT/VTT to LRC: Creating synced lyrics from subtitle files
  • LRC to SRT: Using lyrics as subtitles in video players