# MED_014: fragment in overlay audio URL, how to fix it

Source: https://epubcc.com/epubcheck/med_014/ (updated 2026-11-04)

EPUBCheck MED_014 is an error message: “Media overlay audio file URLs must not have a fragment, but found '#…'.” A media overlay audio URL has a fragment (#part), which is not allowed. The part of the audio file to play is given by clipBegin and clipEnd, not by a fragment in the URL.

- Official message (EPUBCheck 5.4.0): Media overlay audio file URLs must not have a fragment, but found '#%1$s'.
- Default severity: Error

## Typical causes

- Media fragments such as narration.mp3#t=10,20 copied from web audio.
- A script that wrote the clip times into the URL instead of the attributes.

## How to fix it

1. Open the SMIL file and remove the #fragment from the src of each audio element.
2. Move the times into clipBegin and clipEnd, for example <audio src="narration.mp3" clipBegin="10s" clipEnd="20s"/>.
3. Rebuild the EPUB and run EPUBCheck again to confirm the message is gone.

## When it's not this

Fragments are expected in text src (pointing to an element id); those are checked by MED_017.

## 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.