M3U8 Downloader

Introduction

This tool downloads every segment listed in an m3u8 playlist (the index file used by HLS streaming) and merges them into a single video file you can play anywhere. After you paste an m3u8 address, the tool reads the playlist and works out what it is: a master playlist that offers several quality levels, or a media playlist that lists the segments of one rendition. Master playlists let you pick a quality first; media playlists immediately show the segment count, total duration and encryption method. Press start and all segments are fetched concurrently, encrypted segments are decrypted inside your browser, segments that cannot be decrypted or downloaded are skipped, and everything that succeeded is joined in its original order into one .ts (or .mp4) file.

• Automatic quality detection: every rendition is listed with its resolution and bitrate, so you can choose instead of editing URLs by hand.
• Encrypted streams supported: HLS streams protected with AES-128 or AES-256 are decrypted automatically using the key and initialisation vector declared in the playlist.
• Undecryptable segments are skipped: segments using DRM, sample-level encryption or an expired key are dropped, and the rest of the video still merges instead of the whole job failing.
• Merging happens in the browser: the video is never stored on the server, and everything is released when the page closes.

Technical Principles

An m3u8 file is a plain-text index. #EXTINF gives the duration of the segment that follows; #EXT-X-STREAM-INF describes a rendition, with its playlist address on the next line; #EXT-X-KEY declares the encryption method, key address and initialisation vector; #EXT-X-MAP points at the initialisation segment of a fragmented MP4 stream; #EXT-X-BYTERANGE means a segment is only a byte range inside a larger resource; #EXT-X-ENDLIST marks the playlist as complete.

The tool parses those tags, resolves every relative address into an absolute one, then fetches segments in order. For AES-128 and AES-256 it performs CBC decryption in the browser using the declared initialisation vector, falling back to the segment's media sequence number as a 128-bit vector when the playlist does not specify one. Any segment that fails to decrypt, or still fails after a retry, is discarded and counted.

Merging relies on how MPEG-TS is built: a TS file is a sequence of independent 188-byte packets with no global header that must sit at the start, so segments can simply be concatenated into one continuous file. Fragmented MP4 is different — the initialisation segment has to come first, and the following segments are appended to form a valid MP4.

Use Cases

• Offline study: keep HLS course videos you own or have licensed so you can revise without a connection.
• Backing up your own streams: archive replays you published yourself before a platform takes them down.
• Unstable connections: download the whole video first, then watch it without buffering pauses.
• Watching on other devices: move content that only plays on a phone to a computer, set-top box or projector.
• Stream diagnostics: check segment counts, durations and packaging completeness when debugging an encoder or packager.
• Teaching: demonstrate what HLS playlists, TS segments and encryption tags actually look like.

Only download material you own or are licensed to download. Do not use this tool to bypass paywalls or to infringe anyone's rights.

Frequently Asked Questions

Q: Why won't some players open the finished file?

A: The default output is an .ts (MPEG-TS) container, which VLC, PotPlayer, most set-top boxes and smart TVs play directly, but some built-in system players do not support. If the source was a fragmented MP4 stream, the tool outputs .mp4 instead, which is more widely compatible.

Q: The tool says some segments were skipped — does that matter?

A: Only the segments that could not be decrypted or kept failing after a retry are skipped. The rest are still merged in order, so the file plays normally, but you may notice a brief jump in picture or sound at those points.

Q: It says the address is not a valid m3u8 playlist.

A: That means the address returned a web page, a login screen or an error message instead of a playlist. Common causes are an expired link, a required session, or a referer check. Fill in the source page address under Advanced options and try again.

Q: Why is a live stream incomplete?

A: Live or still-growing playlists have no end marker, so only the segments listed at that moment are downloaded. Analyse the playlist again after the broadcast ends to get the full list.

Q: Is the video uploaded to or kept on a server?

A: No. The server only reads the playlist and relays segment bytes on request; decryption and merging happen locally in your browser, and nothing is retained after the page is closed.

Typical Usage

Take a typical encrypted HLS playlist:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:6
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-KEY:METHOD=AES-128,URI="key.bin"
#EXTINF:6.000,
seg-0.ts
#EXTINF:6.000,
seg-1.ts
#EXT-X-ENDLIST

1. Paste the playlist address and press Analyze. The tool recognises it as a media playlist and shows the segment count, total duration and encryption method (AES-128 in this example).
2. If the result is a master playlist with several renditions, choose one first to reach its media playlist.
3. Press Start download. The progress panel reports completed segments, merged size, speed and time left, and counts skipped segments separately.
4. When merging finishes the browser saves the video file automatically; if the download does not start, use the Save video file button.

Related Tools

Before downloading, use HTTP Status Checker to confirm the address is reachable and see what content type it returns, and MIME Type Lookup to check which media type a file extension maps to. DNS Lookup helps when a hostname does not resolve, and My IP Address shows your current outbound IP, which is useful when a stream appears to be geo-restricted.