Free online subtitle converter

What a subtitle converter actually does

A subtitle file is just a list of cues, and every cue is two things, a start and end time and the line of text shown between them. Different formats write those two things down differently. Converting a subtitle file means reading every cue and re-writing it in another format's conventions, without changing when a line appears or what it says. This tool handles the text formats you will actually meet day to day, SubRip (.srt), WebVTT (.vtt), Advanced SubStation (.ass/.ssa), YouTube's SBV (.sbv), MicroDVD (.sub), SAMI (.smi), LRC lyrics (.lrc) and TTML/DFXP (.ttml).

The differences are small but they matter to a fussy player. SRT writes timestamps with a comma before the milliseconds (00:00:01,000). WebVTT uses a period (00:00:01.000) and must begin with a WEBVTT header line. ASS keeps its timing in centiseconds inside a structured [Events] section that references named styles. Hand a player the wrong one of these and you often get nothing on screen at all, which is exactly the problem this converter exists to solve.

When you'd convert, and to what

SRT → VTT (for the web)

Browsers don't play SRT. The HTML5 <video> element and its <track> tag require WebVTT, and so do most web players and many learning platforms. If you are embedding video on a website and your captions are in SRT, convert them to VTT first. Because the two formats are structurally almost identical, this conversion is lossless. Only the timestamp punctuation and the header change.

VTT → SRT (for players and TVs)

The reverse is just as common. Plenty of captions are distributed as VTT, but desktop players like VLC, media servers like Plex and Jellyfin, and most smart TVs and set-top boxes expect the more universal SRT. If a .vtt file refuses to load on your TV or shows up as plain text, convert it to SRT and it will almost certainly behave.

To or from ASS/SSA

Convert ASS → SRT/VTT when you only need the words and timing and want to drop the heavy styling, for example taking an anime fansub's elaborately styled track and turning it into a clean SRT a simple player can read. Convert SRT → ASS when you want a starting point for styling; the tool writes a sensible default style so the file is immediately usable in an editor like Aegisub.

The YouTube, DVD-era and lyrics formats

SBV → SRT: YouTube's caption editor exports .sbv, which almost nothing else reads; convert it to SRT and it works everywhere (see the dedicated SBV to SRT converter). SUB → SRT: MicroDVD .sub files time their lines in video frames instead of seconds, which breaks the moment the frame rate is wrong; the SUB to SRT converter turns them into normal timestamps. SMI → SRT: SAMI files are common with Korean releases and few modern players read them. LRC ↔ SRT: lyric files for music players use LRC; convert LRC to SRT to show lyrics as subtitles over a video, or SRT to LRC for a music app. TTML/DFXP → SRT: captions downloaded from streaming or broadcast services often come as TTML or DFXP XML; converting to SRT makes them universally playable.

What is kept, and what gets dropped

Timing and text always convert exactly. A timestamp is a timestamp in any format, so nothing about when your lines appear is ever altered. What can be lost is styling the destination format simply cannot express. Converting a richly styled ASS file down to SRT strips the fonts, colours, exact on-screen positions and karaoke effects, because SRT has no way to store them; you are left with clean, correctly timed plain text. Basic italics and bold survive between SRT and VTT. Whenever the converter has to drop something, it tells you in a warning panel rather than silently changing your file.

If you want to understand the formats themselves in more depth, including what each one stores and which to reach for, see the guide on subtitle formats explained.

How to convert a subtitle file

• Drag your .srt, .vtt or .ass file into the box above, or click to browse. The tool detects the source format automatically.
• Pick the format you want under Convert to. It defaults to something different from your source.
• Check the preview and any warnings, then click Download to save the converted file.

Common problems and fixes

The accented characters look garbled after converting. That is an encoding problem in the original file, not a conversion problem. Run it through the encoding repair tool first to get clean UTF-8, then convert.

The converted file is out of sync with my video. Converting never changes timing, so the source file was already mistimed. Fix that separately by shifting the subtitle timing or, if the drift grows over time, with the frame-rate converter.

My .sub file won't convert. Two very different things use the .sub extension. Text-based MicroDVD files (lines like {25}{100}Hello) convert fine here. But a .sub that comes paired with an .idx file is VobSub, which stores pictures of text ripped from a DVD, not editable text, so a text converter can't read it. VobSub needs OCR first.

Is my file uploaded anywhere?

No. The conversion runs entirely in your browser using JavaScript. Your subtitle file is never sent to a server, there is no sign-up, and there is no limit on how many files you convert.