How to Sync Subtitles Online – Resync & Subtitle Correction Free
Subtitle sync online: when subtitles are out of sync, use our free subtitle synchronizer to resync subtitles and correct timing. Apply a global delay or advance, or edit each line. No signup.
Table of Contents
When to use a subtitle synchronizer
Use our subtitle sync online tool when you need to resync subtitles or correct timing:
- Subtitles are delayed or ahead of the dialogue (e.g. by a fixed number of seconds)
- You have a new video cut and need to shift all subtitles by the same amount
- You want to fine-tune individual start/end times after a global shift
You can apply a single offset to the whole file (e.g. +2.5 seconds) or edit each line’s start and end times manually for precise control.
Step-by-step: syncing subtitles
Open the Subtitle Sync tool
Go to our Subtitle Sync page. No signup or login required.
Upload your subtitle file
Drag and drop your .srt, .vtt, .ass, or other supported file. All lines will load with their current timestamps.
Apply a global offset (optional)
If the whole file is early or late by the same amount, enter the offset in seconds (positive = delay, negative = advance). Use "Apply to all" or the quick buttons (+1s, -1s, +5s, etc.).
Edit individual times (optional)
Each line shows editable start and end times (HH:MM:SS,mmm). Click a field and type the exact time for that line. Useful after a global shift or for single-line fixes.
Download your synced file
Click "Download Synchronized Subtitles" to get your file in the same format you uploaded.
Tips
- To find the right offset: play the video, note how many seconds the subtitles are off, then enter that value (positive to delay, negative to advance).
- Use the 0.1s buttons for fine-tuning when 1 second is too much.
- After applying a global offset, you can still edit any line’s start/end manually for perfect sync.
Ready to sync?
Use our free Subtitle Sync tool. No signup, no watermarks.
Open Subtitle Sync tool