Subtitle Tools

SMI ↔ SRT Converter and SRT ↔ VTT Converter only change the file format — SMI, SRT and WebVTT are read and written differently by different players, but converting between them doesn't touch when each line appears. Timing problems need one of the three sync tools below instead.

Subtitles can be off in three different ways, each with its own fix:

• Every subtitle is early or late by the same fixed amount, from start to finish? Use Subtitle Sync Adjuster to shift the whole file by one amount, in seconds or milliseconds.
• Subtitles line up at the start but drift further out of sync as the video plays, and you know the source and target frame rates? Use Subtitle FPS Converter. This is the common symptom of a frame-rate mismatch, such as a 25 fps subtitle file used with a 23.976 fps video.
• Timing drifts progressively but you don't know the frame rates — only that it lines up correctly at two specific moments? Use Two-Point Subtitle Sync. Give it a correct pair of times near the start and near the end, and it corrects everything in between.

Subtitle Cleaner strips leftover HTML tags, style codes and stray formatting from the text of each line — it never changes timing. Subtitle Validator instead checks timing itself for problems like overlapping or reversed cues, and can automatically fix the unambiguous ones (like renumbering or trimming whitespace) while leaving judgment calls for you to review. A typical workflow is to fix timing first, then clean the text, then validate the result before using the file.