What is a .SUB file?
SUB files hold subtitles, either as text (MicroDVD, SubViewer) or as bitmap images ripped from a DVD.
- Did you know
- The text-based MicroDVD .sub format dates from the early 2000s.
- The MicroDVD variant cues subtitles by frame number, so it can drift if the video’s frame rate differs.
- A DVD-ripped SUB instead holds bitmap images of the text and pairs with an IDX file giving their timings.
- What Analyser reads
- Identify MicroDVD/SubViewer (SUB) subtitle files. SRT, VTT, and ASS/SSA get full cue parsing (see above).
- Depth of analysis
- .SUB is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .SUB file
- Drag a .SUB file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.
- Related formats
- Browse the full list of supported file types.