# EPUBCheck MED-008: clipBegin after clipEnd, how to fix it

Source: https://epubcc.com/epubcheck/med-008/ (updated 2026-11-04)

EPUBCheck MED-008 is an error message: “The time specified in the clipBegin attribute must not be after clipEnd.” In a media overlay, a clip's clipBegin time is after its clipEnd time. The end of each audio clip must come after its start, or the reading app cannot play the narration for that phrase.

- Official message (EPUBCheck 5.4.0): The time specified in the clipBegin attribute must not be after clipEnd.
- Default severity: Error

## Typical causes

- Swapped or mistyped times in the SMIL file.
- Times written in different formats (seconds and h:mm:ss) and misread when edited by hand.

## How to fix it

1. Open the SMIL file EPUBCheck names and find the audio element at the line it reports.
2. Correct the times so clipBegin is before clipEnd, checking them against the audio file.
3. If the times came from an alignment tool, re-run it rather than editing many clips by hand.
4. Rebuild the EPUB and run EPUBCheck again to confirm the message is gone.

## When it's not this

If both times are equal, the error is MED-009.

## Sources

- EPUB 3.3, §9.2.2.8 The audio element: https://www.w3.org/TR/epub-33/#sec-smil-audio-elem (read 2026-11-04)

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EpubCC.