AI Subtitle Studio

How to convert any subtitle format to SRT

Decades of players, broadcasters and ripping tools have produced a zoo of subtitle formats. SRT won. AI Subtitle Studio reads more than thirty text-based formats and converts them all to clean, universally supported SubRip files — including the obscure ones nothing else opens.

Supported input formats

The converter accepts, among others:

  • Broadcast & professional: TTML / DFXP / XML timed text, EBU STL, SCC and MCC (closed captions), CAP, Teletext-sourced tracks
  • Player-era formats: MicroDVD (.sub text), SAMI/SMI, SubViewer 1/2, VPlayer, MPL2, MPSub, DKS, PJS, JacoSub (JSS), PSB, RealText (RT), USF, TTXT, SBT
  • Modern & web: WebVTT, SBV (YouTube), LRC (lyrics), MOV_TEXT (MP4), ASS/SSA

Both sidecar files and tracks embedded in MKV/MP4/AVI containers are handled — embedded tracks are converted during extraction.

Encoding detection: the silent subtitle killer

Old subtitle files predate UTF-8. A Turkish .sub from 2006 is probably ISO-8859-9; a Chinese .smi might be GB18030 or Big5; Japanese packs are often Shift_JIS. Opened naively, they turn into mojibake — ä, 字幕 and friends.

AI Subtitle Studio detects the source encoding automatically (UTF-8/16, Windows-1252, ISO-8859-9, GB18030/GBK, Big5, Shift_JIS, EUC-KR and more) and writes standards-compliant UTF-8 SRT, so accented and non-Latin characters survive conversion.

Convert any subtitle file to SRT

  1. Drop the file in Drag the subtitle file (or a video containing the track) into the app. The format and text encoding are detected automatically.
  2. Check the preview The editor shows the parsed lines with timing so you can verify everything reads correctly before saving.
  3. Export as SRT Save as UTF-8 .srt — ready for any player, TV, Plex/Jellyfin server or translation workflow.

One converter for every subtitle format

Free to try on Windows & macOS · full version $9.99 one-time · 100% offline

Download free See pricing

Frequently asked questions

What is the best subtitle format to keep?
SRT, unless you specifically need styling (then ASS). SRT is plain text, supported by effectively every player, TV and tool, and is the safest archival format.
Can it convert image-based subtitles too?
Yes — Blu-ray SUP and DVD SUB/IDX are image formats, so they go through the OCR pipeline instead of direct conversion. See the dedicated SUP-to-SRT and SUB/IDX-to-SRT guides.
My converted file shows ’ instead of apostrophes. What happened?
The source encoding was misdetected by whatever tool created the file earlier. Run it through the encoding repair feature, which re-detects and rewrites the text as clean UTF-8.
Does conversion change subtitle timing?
Never. Only the container syntax changes; timestamps are converted with millisecond precision.

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