Cut clips from HLS streams
HLS Clip Cutter loads a public m3u8 playlist, lets you preview the stream, select a start and end time, choose quality and audio tracks, then export a short clip as MP4, WebM, or MKV. It is useful for clipping webinars, live event archives, stream highlights, lectures, test streams, and other HLS sources without downloading the full stream first.
1. HLS Input
This panel is where the tool reads the source stream and discovers what is available before export. Use it first, then move to the timeline once the stream information appears.
- HLS (m3u8) URL. Paste a direct HTTP or HTTPS playlist URL. The stream host must allow browser CORS requests because the playlist and segments are fetched directly by your browser.
- Load from URL. Fetches the playlist, parses variants, checks tracks with Mediabunny, and attaches the stream to the preview player through hls.js when the browser needs it.
- Upload m3u8 File. Reads a local playlist file. This works best when segment URLs inside the playlist are absolute URLs; relative segment paths usually cannot resolve from a local file.
- Quality / Video Track. Shows the variants declared by the master playlist, such as 720p or 1080p. Auto picks the primary/best playable track; a specific variant limits export to that track when possible.
- Audio Track. Chooses the audio rendition to include. Some HLS streams expose one primary audio track; others expose multiple languages or codec variants.
- Preview toggle. Controls whether the browser initializes the preview player. Turn it off when you only need metadata/export or when a source previews poorly but can still be processed.
- Stream Information. Summarizes title, duration or live DVR window, available qualities, audio tracks, detected frame rate, and protocol. If duration says live window, only currently available content can be clipped.
2. Preview & Select Segment
This area is for checking the stream and choosing the exact clip range. The top preview is playback only; the timeline and time inputs decide what gets exported.
- Preview player. Plays the loaded HLS stream. The counter shows current preview time and total detected duration or live window length.
- Playback bar. Lets you seek through the loaded stream for visual checking. Seeking here does not change the exported range by itself.
- Range timeline. The highlighted area is the selected clip. The top slider adjusts start time; the bottom slider adjusts end time.
- Start Time and End Time. Accept values like 00:45:30 or 92:15. When you leave the field, the tool clamps invalid values inside the stream duration.
- Duration. Read-only output length calculated from end time minus start time. This value drives estimated size and export length.
- Quick shift buttons. Move the selected range backward or forward by 10 seconds, 1 minute, or 5 minutes while preserving the clip duration.
3. Advanced Options
These settings control how the clip is written. Keep the defaults for most HLS highlights; change them only when a destination platform or codec requirement is specific.
- Segment Mode. Smart Cut is faster and tries to preserve encoded packets where possible. Precise Cut re-encodes for closer timestamp accuracy, useful when the cut must start very near a chosen frame.
- Output Format. MP4 is the safest choice for sharing and upload. WebM is useful for browser-first workflows. MKV is flexible for archival/testing when codec compatibility varies.
- Video Codec. Auto keeps/copies when the output container supports it. H.264 is the broadest MP4 target. VP9 and AV1 are mainly for WebM/MKV workflows and depend on browser encoder support.
- Audio Codec. Auto keeps/copies when possible. AAC is the common MP4 choice. Opus is efficient for WebM/MKV and voice-heavy streams.
- Keep original audio track. Leave enabled for normal clips. Turn it off only when you need silent video or when an audio track causes export compatibility issues.
4. Export Clip
- Estimated Size. A bitrate-based estimate from the selected variant and clip duration. The final file may differ after copying, remuxing, or re-encoding.
- Cut & Export Clip. Starts browser-side processing with Mediabunny. Progress appears while segments are read, decoded if needed, and written to the target format.
- Preview 10s Clip. Jumps preview playback to the selected start so you can quickly check the cut point before exporting.
- Download Clip. Appears after a successful export and saves the generated file with a filename based on the source and selected time range.
Privacy and technical limits
The playlist and segments are read directly by your browser from the stream host; appkiro does not receive the media file. Export depends on CORS, WebCodecs support, and whether the stream is encrypted. DRM-protected streams, tokenized URLs that expire during processing, and hosts that block browser fetch requests cannot be cut reliably.