Does the validator check spelling or transcription accuracy?

No. It checks caption structure and timing syntax, not language accuracy.

Are overlapping cues treated as invalid?

No. They are counted for review because overlap may be intentional in some files.

Does conversion change the caption words?

No. Valid cue text is preserved while timestamp separators and file structure are serialized for the target format.

Are WebVTT cue settings preserved?

Parsed WebVTT timing-line settings are preserved when the target remains WebVTT. SRT has no equivalent field.

Developer Tools

YouTube SRT & WebVTT Validator Converter

Parse SRT or WebVTT blocks, report structural timing and text errors, then convert valid cues between both formats.

Free browser toolRuns in your browserNo sign-up

SRT detected

3 valid cues

The validator checks timestamp syntax, timing direction and non-empty cue text. It does not validate language accuracy or synchronization with a video.

Parsed cues

Structural errors

Overlaps

Reported for review; not blocked.

00:00:00,000 → 00:00:03,200

Clear captions help viewers follow the explanation.

00:00:03,400 → 00:00:07,100

Review timing, line length and the words on screen.

00:00:07,300 → 00:00:10,800

Then upload the finished caption file with the video.

Private by design. Input is processed inside this browser tab and is not sent to ToolsOnDuty.

About the YouTube SRT & WebVTT Validator Converter

YouTube SRT & WebVTT Validator Converter detects the input format, parses cue blocks and reports missing timing lines, invalid timestamps, end times that do not follow start times and empty cue text.

Valid cues can be serialized as either SubRip or WebVTT and copied or downloaded. Adjacent timing overlaps are counted for review but are not blocked because some caption workflows use intentional overlap.

Structural validation cannot confirm synchronization, spelling, translation quality, speaker identification or accessibility completeness. Review the converted file with the final video.

Key features

Automatic SRT or WebVTT detection
Timestamp-syntax validation
Start-before-end validation
Non-empty cue-text validation
Adjacent-overlap count
SRT-to-WebVTT conversion
WebVTT-to-SRT conversion
Copy and local download

How to use

1Paste the complete SRT or WebVTT file text.
2Review and fix every reported structural issue.
3Check the overlap count and decide whether each overlap is intentional.
4Choose the target format, download it and test the result with the final video.

Examples

Convert a valid SRT file

Input: Three numbered SRT cues with comma-separated milliseconds

Output: WEBVTT file with dot-separated timestamps

Check synchronization and language again after conversion.

Frequently asked questions

Does the validator check spelling or transcription accuracy?: No. It checks caption structure and timing syntax, not language accuracy.
Are overlapping cues treated as invalid?: No. They are counted for review because overlap may be intentional in some files.
Does conversion change the caption words?: No. Valid cue text is preserved while timestamp separators and file structure are serialized for the target format.
Are WebVTT cue settings preserved?: Parsed WebVTT timing-line settings are preserved when the target remains WebVTT. SRT has no equivalent field.

Open a related tool to prepare your files or refine the finished result.