LL-HLS PART-TARGET is not smaller than the target duration
Partial segments are not meaningfully smaller than whole segments, so low latency achieves nothing.
What it means
PART-TARGET declares the length of a partial segment. Here it is as long as, or longer than, EXT-X-TARGETDURATION.
Why it matters
The point of low-latency HLS is that a player can start on a fraction of a segment rather than waiting for a whole one. If a part is the same size as a segment, the player waits just as long — you carry all the complexity of LL-HLS and none of the benefit.
How to fix it
- Set PART-TARGET to a small fraction of the target duration; a third of a second against a four-second segment is typical.
- Shorter parts give lower latency at the cost of more requests, so tune against your CDN’s per-request overhead.
Check your own stream
The free HLS analyzer runs this check on every analysis and links each finding straight back here.
Open the HLS analyzer →Frequently asked questions
- What does "LL-HLS PART-TARGET is not smaller than the target duration" mean?
- PART-TARGET declares the length of a partial segment. Here it is as long as, or longer than, EXT-X-TARGETDURATION.
- Why does it matter?
- The point of low-latency HLS is that a player can start on a fraction of a segment rather than waiting for a whole one. If a part is the same size as a segment, the player waits just as long — you carry all the complexity of LL-HLS and none of the benefit.
- How do I fix it?
- 1. Set PART-TARGET to a small fraction of the target duration; a third of a second against a four-second segment is typical. 2. Shorter parts give lower latency at the cost of more requests, so tune against your CDN’s per-request overhead.
- How can I detect this automatically?
- Paste your HLS streaming URL into StreamTest's free HLS analyzer. It runs this check on every analysis, flags the finding, and links straight back to this page — no sign-up required.
Related HLS checks
- HLS ladder has a bitrate inversionA lower-resolution variant is allocated more bandwidth than a higher-resolution one, so adaptive switching picks the wrong rendition.
- HLS variant is missing the CODECS attributeWithout CODECS, players must download a segment before they can tell whether they can play the rendition at all.
- HLS variant references an undeclared rendition groupA variant points at an AUDIO or SUBTITLES group that has no matching EXT-X-MEDIA entry, which breaks playback on strict players.
- HLS segment is longer than EXT-X-TARGETDURATIONA segment rounds to more than the declared target duration, which violates the HLS specification.
- HLS live window is shorter than three target durationsThe playlist holds too little content, so any player that falls slightly behind runs off the end of the window.
- HLS playlist has no EXT-X-PROGRAM-DATE-TIMEWithout program date-time the stream cannot be mapped to wall-clock time, which breaks DVR seeking and multi-stream alignment.