Caption Cleanroom · E4 local prototype

QA and clean SRT/VTT files for upload.

Analyze locally for timestamp and overlap issues, reflow text toward two lines and 42 characters, convert formats, and download the result.

Private by design.
Files are read in this browser only. Nothing is uploaded, saved, tracked, or sent to an account.

1. Load a caption file

Choose an SRT or VTT file Or paste caption text

2. Clean and export

Output format Local release profile

Advisory checks only: profile thresholds guide review and do not certify a platform upload.

Reflow whitespace and long lines Clamp safe timestamp overlaps to the preceding cue end

Conversion workflow: choose SRT or WebVTT, clean the preview, review the change ledger, then download the converted caption file. A report can be downloaded with or without a clean preview.

Unsafe timing errors stay visible. Overlap clamping is opt-in and is skipped when it would create a zero-length cue.

Before export: parser and timestamp errors are hard findings that can block cleaning; readability and release-profile results are heuristic advisories. Review the actual caption text and target platform requirements before uploading—this tool does not certify accessibility or platform acceptance.

QA results

No file analyzed yet

Analyze a caption file to see the heuristic readability report.

Cleaned preview

Visible change ledger

Clean preview to see exactly which cues changed.