CuePatch field guide
How to sync SRT subtitles on a Mac
When every subtitle lands the same amount early or late, the file usually needs a constant timing offset—not hundreds of manual edits. The repair is straightforward once you measure one reliable dialogue point.
1. Confirm that the delay is constant
Play the beginning, middle and end of the video. If captions are about the same number of milliseconds early or late at all three points, use an offset. If the difference grows over time, you have drift and should use a speed correction instead.
2. Measure a clear sync point
Choose a visible line with a sharp sound or obvious mouth movement. Note when the subtitle starts and when the spoken line actually begins. The difference is your offset. Positive values move captions later; negative values move them earlier.
3. Preview before exporting
Apply the offset to a copy of the SRT and inspect several cues. Check that no timestamps were pushed below zero and that cues still end after they begin. A validator should also flag new overlaps.
4. Export a new SRT copy
Keep the original file intact and use a descriptive suffix such as -synced. Test the exported file in the player or editor used for delivery. CuePatch automates these steps locally and records the applied offset in its export manifest.