HLS validator.Check any .m3u8.
Paste a link or the playlist text. The validator checks it against the HLS spec and what players expect — tags and versions, codecs, audio and subtitle groups, segment timing, encryption — and follows a master playlist into its media playlists.
A master or media playlist. Try: ·
Errors, warnings and notes.
Structure
#EXTM3U first, no master and media tags in one file, required BANDWIDTH and TARGETDURATION, segments present.
Groups and languages
Every AUDIO and SUBTITLES group a variant refers to exists, one DEFAULT per group, unique names, LANGUAGE set.
Variants
CODECS, RESOLUTION and FRAME-RATE declared, no duplicates, a light enough rendition for slow networks.
Segment timing
No segment longer than the target duration, even segment lengths, a live window of at least three target durations.
Versions and tags
EXT-X-VERSION high enough for EXT-X-MAP, byte ranges, decimal durations and IVs; VOD playlists end with EXT-X-ENDLIST.
Encryption
Key method and URI, keys over http, SAMPLE-AES that needs a special player, mixed content.
Not every warning is a bug.
Errors break the spec — some players will refuse the stream. Warnings play, but badly somewhere: slow start, no quality cap, subtitles that never show. Notes are recommendations from the HLS authoring guidelines.
Questions about the validator.
Is my playlist sent anywhere?
No. Your browser fetches the playlists directly from your server and checks them on the page; dodocast never sees the link or the text.
The link doesn’t load — what now?
The server probably doesn’t send CORS headers, so the browser can’t read it from another site. Open the playlist, copy its text and use “Paste text”.
Does it check segments too?
No, only playlists: the master and up to eight media playlists it links to. To see whether the segments actually play, open the stream in the HLS player.
Is it the same as Apple’s Media Stream Validator?
It’s a quick check of the playlists in the browser. Apple’s tool also downloads and analyzes the media, so run it before shipping to Apple devices at scale.
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